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General Category => Yeast and Fermentation => Topic started by: Saccharomyces on September 17, 2020, 04:59:59 pm

Title: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 17, 2020, 04:59:59 pm
Well, I posted my first blog entry in over four years. The blog entry is entitled "Shaken, not Stirred: The Stir Plate Myth Buster" (https://www.experimentalbrew.com/blogs/saccharomyces/shaken-not-stirred-stir-plate-myth-buster).   I proofread it several times, but like any publication, it will more than likely get revised over time.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Wilbur on September 17, 2020, 07:47:53 pm
It's an interesting read, but it have a few questions.

Do you have any sources I can read that support your arguments against stir plates?

Isn't intense shaking also going to induce shear stress?

If you pitch the whole starter, then don't you usually pitch the early flocculating yeast anyway? Isn't pitching early flocculating yeast an issue with yeast cropping/sourcing?

The last I feel often gets confounded, I feel I often read complaints against a particular method in hobbies when the method is independent of the end result. Is the primary issue using a stir plate, or pitching a starter that's fermented out? I typically use a stir plate but start my starter an hour or two before the brew day. When I'm done brewing, the starter is usually at high krausen and I pitch the whole thing.

Thanks for the good read.

Sent from my Pixel 2 XL using Tapatalk

Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Village Taphouse on September 18, 2020, 10:16:42 am
I am planning on trying the SNS method shortly.  I am not scientific in any way but I am open-minded and will generally try just about anything.  One thing that peeves me is people who like to criticize something without ever trying it.  Two things:  Is there a link to the method of creating a SNS starter?  I thought someone mentioned it elsewhere but I have never seen it.  Also, I happen to own a stirplate and I use pure O2 (O2 canister and stone) in the starter and then place it on the stirplate and I get quick activity and I generally pitch the entire volume.  I do not understand the "foul-smelling" thing.  My stirplate starters do not smell foul.  Yes, I have made starters that appeared to be contaminated (clearly my fault) and that starter would be tossed out.  But generally my starters smell like fresh yeast.  Thanks for the link to the post.  Always good to stay on top of things. 
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: denny on September 18, 2020, 11:07:30 am
I am planning on trying the SNS method shortly.  I am not scientific in any way but I am open-minded and will generally try just about anything.  One thing that peeves me is people who like to criticize something without ever trying it.  Two things:  Is there a link to the method of creating a SNS starter?  I thought someone mentioned it elsewhere but I have never seen it.  Also, I happen to own a stirplate and I use pure O2 (O2 canister and stone) in the starter and then place it on the stirplate and I get quick activity and I generally pitch the entire volume.  I do not understand the "foul-smelling" thing.  My stirplate starters do not smell foul.  Yes, I have made starters that appeared to be contaminated (clearly my fault) and that starter would be tossed out.  But generally my starters smell like fresh yeast.  Thanks for the link to the post.  Always good to stay on top of things.

The method couldn't be more straightforward.  Put 1 qt of 1.035 wort in a 1 gal. container.  Shake until it's full of foam.  Pitch yeast.  Pitch entire starter at high krauesen..or in my case, as close as possible.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Village Taphouse on September 18, 2020, 11:42:57 am
I am planning on trying the SNS method shortly.  I am not scientific in any way but I am open-minded and will generally try just about anything.  One thing that peeves me is people who like to criticize something without ever trying it.  Two things:  Is there a link to the method of creating a SNS starter?  I thought someone mentioned it elsewhere but I have never seen it.  Also, I happen to own a stirplate and I use pure O2 (O2 canister and stone) in the starter and then place it on the stirplate and I get quick activity and I generally pitch the entire volume.  I do not understand the "foul-smelling" thing.  My stirplate starters do not smell foul.  Yes, I have made starters that appeared to be contaminated (clearly my fault) and that starter would be tossed out.  But generally my starters smell like fresh yeast.  Thanks for the link to the post.  Always good to stay on top of things.

The method couldn't be more straightforward.  Put 1 qt of 1.035 wort in a 1 gal. container.  Shake until it's full of foam.  Pitch yeast.  Pitch entire starter at high krauesen..or in my case, as close as possible.
Thank you.  I thought that was all there was to it but I wanted to make sure there were no other pieces.  So, step 1: get a gallon container with a lid.  I have a lot of ½ gallon glass growlers but I don't think I have anything gallon-sized with a lid on it.  I'll work on that.  I have some 838 waiting patiently to be woken up so I may employ the SNS method on it.  Cheers Denny. 

EDIT:  Also, I made a White Labs 01 starter recently on the stirplate.  I notice that [depending on the strain], the starter will have a faint "apple pie" kind of thing going on but other than the rare contaminated starter, my starters don't smell foul.  Maybe the OP can tell us what he's experiencing and maybe a theory as to what is causing it. 
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: narvin on September 18, 2020, 11:53:52 am
One question: I always shake my starters to aerate, but I noticed that the foam has little to no head retention unless I’m repitching yeast from a previous batch.  So when starting from a white labs pack, I can’t really get much foam in the jug.  I use canned starter wort (unhopped) that I make specifically for this, not DME.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Village Taphouse on September 18, 2020, 12:02:51 pm
One question: I always shake my starters to aerate, but I noticed that the foam has little to no head retention unless I’m repitching yeast from a previous batch.  So when starting from a white labs pack, I can’t really get much foam in the jug.  I use canned starter wort (unhopped) that I make specifically for this, not DME.
Interesting.  I have never tried a SNS starter but I envision that my wort would be the same way... foam forms but quickly dissipates. 
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: denny on September 18, 2020, 12:24:05 pm
I am planning on trying the SNS method shortly.  I am not scientific in any way but I am open-minded and will generally try just about anything.  One thing that peeves me is people who like to criticize something without ever trying it.  Two things:  Is there a link to the method of creating a SNS starter?  I thought someone mentioned it elsewhere but I have never seen it.  Also, I happen to own a stirplate and I use pure O2 (O2 canister and stone) in the starter and then place it on the stirplate and I get quick activity and I generally pitch the entire volume.  I do not understand the "foul-smelling" thing.  My stirplate starters do not smell foul.  Yes, I have made starters that appeared to be contaminated (clearly my fault) and that starter would be tossed out.  But generally my starters smell like fresh yeast.  Thanks for the link to the post.  Always good to stay on top of things.

The method couldn't be more straightforward.  Put 1 qt of 1.035 wort in a 1 gal. container.  Shake until it's full of foam.  Pitch yeast.  Pitch entire starter at high krauesen..or in my case, as close as possible.
Thank you.  I thought that was all there was to it but I wanted to make sure there were no other pieces.  So, step 1: get a gallon container with a lid.  I have a lot of ½ gallon glass growlers but I don't think I have anything gallon-sized with a lid on it.  I'll work on that.  I have some 838 waiting patiently to be woken up so I may employ the SNS method on it.  Cheers Denny. 

EDIT:  Also, I made a White Labs 01 starter recently on the stirplate.  I notice that [depending on the strain], the starter will have a faint "apple pie" kind of thing going on but other than the rare contaminated starter, my starters don't smell foul.  Maybe the OP can tell us what he's experiencing and maybe a theory as to what is causing it.

Ken, I used a gal. glass jug that had contained apple juice.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: EnkAMania on September 18, 2020, 01:04:49 pm
I've done the shaken and not stirred my last couple of batches.  I still do my vitality starter, 550 ml starter, pitched 4-5 hours after shaking. 
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: kramerog on September 18, 2020, 01:14:00 pm
Has anyone figured out the limits to SNS method?  Such as good for SG up to 1.xxxx?  Between 1.xxx and 1.yyy, make a 1.5 qt SNS starter?  How fresh does the liquid yeast have to be?
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: denny on September 18, 2020, 01:18:01 pm
Has anyone figured out the limits to SNS method?  Such as good for SG up to 1.xxxx?  Between 1.xxx and 1.yyy, make a 1.5 qt SNS starter?  How fresh does the liquid yeast have to be?

I have used it on ales up to 1.075ish and lagers up to 1.065.  Might work on bigger beers, but those are the limits of what I've tried.  But your question seems to imply cel count, which is not the way SNS works.  I have not tracked the date of the yeast, but off the top of my head it's been anywhere from a couple weeks to many months.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 18, 2020, 02:10:36 pm
Do you have any sources I can read that support your arguments against stir plates?

Here is a better question; namely, have you ever seen a stir plate mentioned in a published yeast research paper?  That is because a stir plate is not the correct device for cell culture.  The correct mechanical device is an orbital shaker.  That is what White Labs uses in the room where they grow seed cultures for propagation.   The use a stir plate in cell culture is an amateur brewer creation that is based on an incomplete understanding of brewing yeast strains.  As I mentioned in my blog entry, brewing yeast strains do not need to be stirred to remain in suspension because they belong to the NewFlo phenotype and the claim that they can exceed maximum cell density is nonsense. Brewing yeast strains do not truly respire in wort above the Crabtree threshold, which causes overflow metabolism.  What they do is shunt O2 and carbon from the fermentative metabolic pathway to the respirative metabolic pathway for the production of ergosterol and unsaturated fatty acids (UFA) during the lag phase, the spinning the culture continuously adds O2 to the culture is based on not only not understanding how brewing yeast strains operate, it is based on faulty information because very little O2 is entering the flask after CO2 production occurs due to CO2 being heavier than air.   About the only beneficial thing spinning does is help to drive off CO2 gas.  Other than that, the downsides of a stir plate outweigh the upsides.

As far as to references, I have pieced a lot information together from various publications I have read over the years.  I did not cherry pick my information.  I continuously check for new research.  If you use the search term "brewers yeast respiration Crabtree." you will be rewarded with links to many publications.   

Here is one such link:  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4429655/

The abstract from that publication.

"The capability to ferment sugars into ethanol is a key metabolic trait of yeasts. Crabtree-positive yeasts use fermentation even in the presence of oxygen, where they could, in principle, rely on the respiration pathway. This is surprising because fermentation has a much lower ATP yield than respiration (2 ATP vs. approximately 18 ATP per glucose). While genetic events in the evolution of the Crabtree effect have been identified, the selective advantages provided by this trait remain controversial. In this review we analyse explanations for the emergence of the Crabtree effect from an evolutionary and game-theoretical perspective. We argue that an increased rate of ATP production is likely the most important factor behind the emergence of the Crabtree effect."

Who ever made the claim that stir plates produce more yeast because they continuously aerate the culture knew nothing about how the Crabtree effect.

Quote
Isn't intense shaking also going to induce shear stress?

Yes, it will, which I noted in the blog entry.  As I mentioned, the starter can be pitched before or after shaking. If one pitches after shaking, it is best to gently shake the culture a second time to disperse the cells.

Quote
If you pitch the whole starter, then don't you usually pitch the early flocculating yeast anyway? Isn't pitching early flocculating yeast an issue with yeast cropping/sourcing?

I think that you are misreading into what I wrote or reading into it.  Both methods result in early flocculators.  The difference is that they are not held in suspension with an SNS starter.  The whole argument that a yeast culture needs to be spun to remain in suspension demonstrates a lack of understanding of the NewFlo phenotype (you can Google that one too).

Quote
The last I feel often gets confounded, I feel I often read complaints against a particular method in hobbies when the method is independent of the end result. Is the primary issue using a stir plate, or pitching a starter that's fermented out? I typically use a stir plate but start my starter an hour or two before the brew day. When I'm done brewing, the starter is usually at high krausen and I pitch the whole thing.

It is primarily an issue of stir plates being promoted as the best way to make starters to new brewers, which is not based on peer-reviewed science.  It is based on amateur brewer dogma just a like the dogma of using a secondary fermentation vessel to avoid autolysis.  Luckily, the use of secondary fermentation vessels has died off.  My goal is to educate new and exiting brewers about the fallacy of promoting stir plates as the best way to make a starter because it is not backed up by science. The absolute best way to make a starter is to saturate the starter wort with an O2 bottle and a diffusion stone before the culture is pitched (pure O2 provides for a higher saturation level than air). However, that method imposes cost and the responsibility of keeping a diffusion stone sanitary.  As mentioned in the blog entry, my method of making a starter is not do all, be all method for making a starter.  What it is is simple, low cost, and highly effective.  The proof is in the pudding that few of the people who have tried SNS after using a stir plate went back to using a stir plate.  Why would a brewer work harder than he/she needed to in order to achieve a comparable result?

By the way, I am not targeting you.  I expect to get heavy blow back from the blog entry.  People do not like to feel like they have been taken for a ride based on faulty information.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 18, 2020, 02:11:08 pm
The method couldn't be more straightforward.  Put 1 qt of 1.035 wort in a 1 gal. container.  Shake until it's full of foam.  Pitch yeast.  Pitch entire starter at high krauesen..or in my case, as close as possible.

It's that simple! :)
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 18, 2020, 02:15:08 pm
One question: I always shake my starters to aerate, but I noticed that the foam has little to no head retention unless I’m repitching yeast from a previous batch.  So when starting from a white labs pack, I can’t really get much foam in the jug.  I use canned starter wort (unhopped) that I make specifically for this, not DME.

The head falls fairly quickly due to the low gravity of the wort.  However, I can usually shake hard enough to transform around 500ml of wort into foam.  The starter in the photo in the blog entry contained 1L of starter wort before shaking. As one can see, the liquid line is near 500ml.

What I have noticed with British brewers is that they use ribbed 5L water bottles and get an amazing amount of foam.  The ribs are clearly causing turbulence that creates more foam that a straight-sided container.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: ynotbrusum on September 18, 2020, 02:28:47 pm
Has anyone figured out the limits to SNS method?  Such as good for SG up to 1.xxxx?  Between 1.xxx and 1.yyy, make a 1.5 qt SNS starter?  How fresh does the liquid yeast have to be?

I have used it on ales up to 1.075ish and lagers up to 1.065.  Might work on bigger beers, but those are the limits of what I've tried.  But your question seems to imply cel count, which is not the way SNS works.  I have not tracked the date of the yeast, but off the top of my head it's been anywhere from a couple weeks to many months.

Just casual observation, but I made a 10 gallon batch of lager (1.050 ish) that I pitched 2 separate SNS starters into.  A subsequent batch was pitched with just one 1 L SNS and it fermented out in roughly the same time frame as the 2 starter batch, certainly less than a days’ difference overall.  Just a couple data points and YMMV, of course.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 18, 2020, 02:39:04 pm
Just casual observation, but I made a 10 gallon batch of lager (1.050 ish) that I pitched 2 separate SNS starters into.  A subsequent batch was pitched with just one 1 L SNS and it fermented out in roughly the same time frame as the 2 starter batch, certainly less than a days’ difference overall.  Just a couple data points and YMMV, of course.

That is because yeast cultures are like nuclear weapons in that close is good enough. :)
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: jeffy on September 18, 2020, 03:22:27 pm
I remember the very first AHA conference I went to in New Orleans in 1996.  A speaker there (she was either a lab person or a pro brewer) was making the claim that stir plate starters produce 4 times as much yeast as starters without a stir plate.  Of course that was along time ago, but that's what lead me to buy my first stir plate.
That was the same year that Larry Bell gave a talk about Eccentric beer and passed out a hand written page and a half list of all the ingredients including Levi Garrett chewing tobacco.  Good times.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: narvin on September 18, 2020, 03:45:26 pm
One question: I always shake my starters to aerate, but I noticed that the foam has little to no head retention unless I’m repitching yeast from a previous batch.  So when starting from a white labs pack, I can’t really get much foam in the jug.  I use canned starter wort (unhopped) that I make specifically for this, not DME.

The head falls fairly quickly do to the low gravity of the wort.  However, I can usually shake hard enough to transform around 500ml of wort into foam.  The starter in the photo in the blog entry contained 1L of starter wort before shaking. As one can see, the liquid line is near 500ml.

What I have noticed with British brewers is that they use ribbed 5L water bottles and get an amazing amount of foam.  The ribs are clearly causing turbulence that creates more foam that a straight-side container.

Interesting.  I may have to try a different container. When I throw in saved yeast from a previous batch, I can usually get a pretty good foam, possibly from some additional proteins from the beer or hops.  Without, I'm lucky if the foam is an inch or two in a 1 gallon jug.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: denny on September 18, 2020, 04:13:55 pm
Mark, I have a question...lately I've been brewing 12 gal. batches on the Grainfather G70.  I split them into 2 fermenters, 6 gal. each.  Is there any chance that a 1 qt. SNS starter could be split be split between the 2?  Theoretically, do you think it would work?  I have no problem giving it a go if you think it might be feasable.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Wilbur on September 18, 2020, 04:30:36 pm
Do you have any sources I can read that support your arguments against stir plates?

Here is a better question; namely, have ever seen a stir plate mentioned in a published yeast research paper?  That is because a stir plate is not the correct device for cell culture.  The correct mechanical device is an orbital shaker.  That is what White Labs uses in the room where they grow seed cultures for propagation.   The use a stir plate in cell culture is amateur brewer creation that is based on an incomplete understanding of brewing yeast strains.  As I mentioned in my blog entry, brewing yeast strains do not need to be stirred to remain in suspension because they belong to the NewFlo phenotype and the claim that they can exceed maximum cell density is nonsense. Brewing yeast strains do not truly respire in wort above the Crabtree threshold, which causes overflow metabolism.  What they do is shunt O2 and carbon from the fermentative metabolic pathway to the respirative metabolic pathway for the production of ergosterol and unsaturated fatty acids (UFA) during the lag phase, the spinning the culture continuously adds O2 to the culture is based on not only not understanding how brewing yeast strains operate, it is based on faulty information because very little O2 is entering the flask after CO2 production occurs due to CO2 being heavier than air.   About the only beneficial thing spinning does is help to drive off CO2 gas.  Other than that, the downsides of a stir plate outweigh the upsides.

As far as to references, I have pieced a lot information together from various publications I have read over the years.  I did not cherry pick my information.  I continuously check for new research.  If you use the search term "brewers yeast respiration Crabtree." you will be rewarded with links to many publications.   

Here is one such link:  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4429655/

The abstract from that publication.

"The capability to ferment sugars into ethanol is a key metabolic trait of yeasts. Crabtree-positive yeasts use fermentation even in the presence of oxygen, where they could, in principle, rely on the respiration pathway. This is surprising because fermentation has a much lower ATP yield than respiration (2 ATP vs. approximately 18 ATP per glucose). While genetic events in the evolution of the Crabtree effect have been identified, the selective advantages provided by this trait remain controversial. In this review we analyse explanations for the emergence of the Crabtree effect from an evolutionary and game-theoretical perspective. We argue that an increased rate of ATP production is likely the most important factor behind the emergence of the Crabtree effect."

Who ever made the claim that stir plates produce more yeast because they continuously aerate the culture knew nothing about how the Crabtree effect.

Quote
Isn't intense shaking also going to induce shear stress?

Yes, it will, which I noted in the blog entry.  As I mentioned, the starter can be pitched before or after shaking. If one pitches after shaking, it is best to gently shake the culture a second time to disperse the cells.

Quote
If you pitch the whole starter, then don't you usually pitch the early flocculating yeast anyway? Isn't pitching early flocculating yeast an issue with yeast cropping/sourcing?

I think that you are misreading into what I wrote or reading into it.  Both methods result in early flocculators.  The difference is that they are not held in suspension with an SNS starter.  The whole argument that a yeast culture needs to be spun to remain in suspension is demonstrates a lack of understanding of the NewFlo phenotype (you can Google that one too).

Quote
The last I feel often gets confounded, I feel I often read complaints against a particular method in hobbies when the method is independent of the end result. Is the primary issue using a stir plate, or pitching a starter that's fermented out? I typically use a stir plate but start my starter an hour or two before the brew day. When I'm done brewing, the starter is usually at high krausen and I pitch the whole thing.

It is primarily an issue of stir plates being promoted as the best way to make starters to new brewers, which is not based on peer-reviewed science.  It is based on amateur brewer dogma just a like the dogma of using a secondary fermentation vessel to avoid autolysis.  Luckily, the use of secondary fermentation vessels has died off.  My goal is to educate new and exiting brewers about the fallacy of promoting stir plates as the best way to make a starter because it is not backed up by science. The absolute best way to make a starter is to saturate the starter wort with an O2 bottle and a diffusion stone before the culture is pitched (pure O2 provides for a higher saturation level than air). However, that method imposes cost and the responsibility of keeping a diffusion stone sanitary.  As mentioned in the blog entry, my method of making a starter is not do all, be all method for making a starter.  What is is simple, low cost, and highly effective.  The proof is in the pudding that few of the people who have tried SNS after using a stir plate went back to using a stir plate.  Why would a brewer work harder than he/she needed to in order to achieve a comparable result?

By the way, I am not targeting you.  I expect to get heavy blow back from the blog entry.  People do not like to feel like they have been taken for a ride based on faulty information.
Targeting like this leads to more productive discussions about brewing. I'm not worried about it at all.

I've always understood stirring to be about removing carbon dioxide (shown to be toxic to yeast at high enough concentrations), at least after yeast starts reproducing. I'm also under the impression oxygen intake is limited by CO2 off gassing and creating a positive pressure effect, I believe CO2 being heavier than air is irrelevant when talking about moving gasses.

I don't have any beefs with SNS, I tend to use my stir plate to prevent blowoff with starters. It was also a gift, I probably wouldn't have spent any money on it either.

Sent from my Pixel 2 XL using Tapatalk

Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 19, 2020, 06:35:32 am
Mark, I have a question...lately I've been brewing 12 gal. batches on the Grainfather G70.  I split them into 2 fermenters, 6 gal. each.  Is there any chance that a 1 qt. SNS starter could be split be split between the 2?  Theoretically, do you think it would work?  I have no problem giving it a go if you think it might be feasable.

It should work for beers that are up to 1.060.   A lot of people used to pitch 500ml starters.  The only way to know for certain if it will achieve acceptable results for you is to try it.  I would be cautious with worts above 1.060, that is, unless you have access to an O2 bottle.  Higher osmotic pressure combined with increasing difficulty when it comes to dissolving O2 as gravity increases makes underpitching a risky endeavor.  High osmotic pressure leads to water being drawn out of the cells, which, in turn, causes a loss in turgor pressure.  Yeast cells without healthy cell walls and plasma membranes wrinkle and implode.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: mabrungard on September 19, 2020, 06:41:37 am
I like spinning and continuously aerating a starter to proof the yeast.  I do chill and decant the spent wort.  But then during chilled wort runoff, I run oxygenated wort into the beaker and give it some good shaking and let it get to work for a few hours before pitching. 
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 19, 2020, 06:51:08 am
I remember the very first AHA conference I went to in New Orleans in 1996.  A speaker there (she was either a lab person or a pro brewer) was making the claim that stir plate starters produce 4 times as much yeast as starters without a stir plate.  Of course that was along time ago, but that's what lead me to buy my first stir plate.

Yes, that may have been the genesis of stir plate adoption, but it is based on faulty information.  That research did not include direct O2 injection. It did include periodic shaking, but not an intense initial shake in an oversized container to increase 02 absorption.  The periodic shaking was performed using an Erlenmeyer flask with not much in the way of headspace.  The focus was more on agitation than O2 absorption.  The one thing that we know for certain is that if a starter reaches high krausen, it has reached maximum cell density beyond which replication is for replacement only, which means that we can get an overall higher cell count in the sediment if we allow a starter to ferment beyond high krausen, but we cannot get get a higher viable cell count.  The liquid cultures that are being sold today are huge compared the liquid cultures that we used in the 90s.  Pitching a smack pack without a starter was pure lunacy because it resulted in lag times measured in days.  Very few sane people did it more than one time.  Today, a relatively new White Labs culture can be pitched into 5 gallons without a starter. That is because the cell count is so high.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 19, 2020, 06:59:42 am
I like spinning and continuously aerating a starter to proof the yeast.  I do chill and decant the spent wort.  But then during chilled wort runoff, I run oxygenated wort into the beaker and give it some good shaking and let it get to work for a few hours before pitching.

The reality is that spinning is not necessary.  It adds absolutely no value because most brewing yeast strains do not need to be spun to stay in suspension because they belong to the NewFlo phenotype and the strains that are not NewFlo are Flo1. Now, adding O2 is on the money.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Kevin on September 19, 2020, 07:51:40 am

... The proof is in the pudding that few of the people who have tried SNS after using a stir plate went back to using a stir plate.  Why would a brewer work harder than he/she needed to in order to achieve a comparable result?

Count me in that group. I stumbled upon a thread talking about the SNS method a little over a year ago and tried it. My stir plate has been on a back shelf gathering dust ever since.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: chezteth on September 19, 2020, 08:08:08 am
I have used the SNS method with ales with great success. Now I'm curious about using this method with lagers.

If I brew a pilsner, how many packs of liquid yeast should I use in the 1 liter starter? Is one pack enough? Or, should I use 2 packs in the 1 liter starter? Or, should I make a larger starter with 2 packs?

Cheers,
Brandon

Sent from my Pixel 2 XL using Tapatalk

Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: denny on September 19, 2020, 08:38:40 am
Mark, I have a question...lately I've been brewing 12 gal. batches on the Grainfather G70.  I split them into 2 fermenters, 6 gal. each.  Is there any chance that a 1 qt. SNS starter could be split be split between the 2?  Theoretically, do you think it would work?  I have no problem giving it a go if you think it might be feasable.

It should work for beers that are up to 1.060.   A lot of people used to pitch 500ml starters.  The only way to know for certain if it will achieve acceptable results for you is to try it.  I would be cautious with worts above 1.060, that is, unless you have access to an O2 bottle.  Higher osmotic pressure combined with increasing difficulty when it comes to dissolving O2 as gravity increases makes underpitching a risky endeavor.  High osmotic pressure leads to water being drawn out of the cells, which, in turn, causes a loss in turgor pressure.  Yeast cells without healthy cell walls and plasma membranes wrinkle and implode.

Likely to be more like 1.065.  I'm gonna give it a go with WY1217.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: denny on September 19, 2020, 08:39:41 am
I like spinning and continuously aerating a starter to proof the yeast.  I do chill and decant the spent wort.  But then during chilled wort runoff, I run oxygenated wort into the beaker and give it some good shaking and let it get to work for a few hours before pitching.

Have you ever tried SNS to compare?  I feel like I get healthier yeast than when I used a stir plate.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: denny on September 19, 2020, 08:41:30 am
I have used the SNS method with ales with great success. Now I'm curious about using this method with lagers.

If I brew a pilsner, how many packs of liquid yeast should I use in the 1 liter starter? Is one pack enough? Or, should I use 2 packs in the 1 liter starter? Or, should I make a larger starter with 2 packs?

Cheers,
Brandon

Sent from my Pixel 2 XL using Tapatalk

I have made lagers with SNS many times.  One pack is enough.  When you talk about using more, you are falling into the cell count trap.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 19, 2020, 09:17:38 am
I have made lagers with SNS many times.  One pack is enough.  When you talk about using more, you are falling into the cell count trap.

Brandon,

I will add to Denny’s comment by saying that yeast cell counts have been overblown in the amateur brewing community. I blame this phenomenon on the heavy use of brewing software. The yeast biomass grows exponentially at a rate of 2^n, where the symbol “^” denotes raised to the power of and n is the number of replication periods. Under optimal conditions the replication period is around 90 minutes. We usually use yeast below optimal growth temperature, which lengthens the replication period, but to drive this information home, the difference between 200B cells and 400B cells is one replication period. The difference between 200B cells and 800B cells is two replication periods. What matters is yeast cell health going into the fermentation and the amount of dissolved O2 in the wort.

If you would like to know more about this subject, read my blog entry entitled “Yeast Cultures are Like Nuclear Weapons” (https://www.experimentalbrew.com/blogs/saccharomyces/yeast-cultures-are-nuclear-weapons).
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 19, 2020, 01:04:54 pm
To open up another can of worms, the practice of pitching cooler and letting the fermentation come up to temperature is also mostly homebrewing dogma that was popularized by Jamie Zainasheff.  I challenge anyone to go on a homebrewing forum call BS on that one.  I pitch a few degrees higher than fermentation temperature and let the fermentation come down in temperature. Why? Because it shortens lag time and speeds up exponential growth, both of which are good if one has solid wort and the proper yeast strain for the job at hand.  I exposed the fallacy of starting ales cooler and letting them come up to fermentation temperature to prevent the overproduction of unwanted compounds in the "Factors Affecting Metabolic Production" section of my blog entry entitled "Have You Seen Ester?" (https://www.experimentalbrew.com/blogs/saccharomyces/have-you-seen-ester).  While a fast exponential growth phase does often result in a higher level of metabolites, wort composition and yeast genetics have a greater impact on ester and higher alcohol production. 

With the above said, I am not going to attempt to slay the "pitch cooler" dragon.  I am happy with attempting to make stir plates an optional piece of equipment. New brewers usually have finite resources.  The last thing that new brewers need to do is spend good money on a piece of equipment that was not designed for cell culture when there are cheaper alternatives that work as just as well, if not better.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: denny on September 19, 2020, 01:29:27 pm
Like "close enough is good enough" for yeast, I've found the same true with temp.  My preference is to go a bit cooler.  If I'm a bit warmer, no big deal.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: EnkAMania on September 19, 2020, 01:38:16 pm
I pitch above and bring down simply because it is a lot easier on my system to lower temp than it is to raise it.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: BrewBama on September 19, 2020, 03:01:24 pm
I pitch at target +/- 5*F.


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Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: denny on September 19, 2020, 03:03:19 pm
I pitch at target +/- 5*F.


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I have a similar range. I have to admit it's gotten a bit broader since I started using glycol chiller conical.  I can adjust temp pretty quickly with them so it's less of an issue to get it to pitch temp before the wort goes into the fermenter.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 19, 2020, 05:06:11 pm
Like "close enough is good enough" for yeast, I've found the same true with temp.  My preference is to go a bit cooler.  If I'm a bit warmer, no big deal.

I concur! There have been times where I accidentally chilled my wort below fermentation temp when I was using a counterflow chiller in the winter (the public water supply here gets pretty darn cold in the dead of winter).  However, like you, I have not experienced a big difference pitching +/- a few degrees, which leads me to believe that pitching low and letting the fermentation rise is just more amateur brewing dogma.  Now, pitching at 75F is an entirely different subject, that is, unless a culture does well at 75F.  That is why it is critical to pitch the culture that meets the job at hand.  If the fermentation is going to be warm, pitch a culture that can get the job done without throwing a ton of metabolic trash.  I like how the Belgians learned to brew with the seasons until the advent of mechanical refrigeration. 
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: chezteth on September 19, 2020, 07:01:06 pm
I have made lagers with SNS many times.  One pack is enough.  When you talk about using more, you are falling into the cell count trap.

Brandon,

I will add to Denny’s comment by saying that yeast cell counts have been overblown in the amateur brewing community. I blame this phenomenon on the heavy use of brewing software. The yeast biomass grows exponentially at a rate of 2^n, where the symbol “^” denotes raised to the power of and n is the number of replication periods. Under optimal conditions the replication period is around 90 minutes. We usually use yeast below optimal growth temperature, which lengthens the replication period, but drive this information, the difference between 200B cells and 400B cells is one replication period. The difference between 200B cells and 800B cells is two replication periods. What matters is yeast cell health going into the fermentation and the amount of dissolve O2 in the wort.

If you would like to know more about this subject, read my blog entry entitled “Yeast Cultures are Like Nuclear Weapons” (https://www.experimentalbrew.com/blogs/saccharomyces/yeast-cultures-are-nuclear-weapons).
Thanks Denny & Saccharomyces! I appreciate the clarification. I'm looking forward to issuing the SNS method for a lager!

Cheers,
Brandon

Sent from my Pixel 2 XL using Tapatalk

Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: denny on September 20, 2020, 08:31:28 am
Mark, when you say "unless a culture does well" are you referring to fermentation performance or beer quality?
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 20, 2020, 09:27:34 am
Mark, when you say "unless a culture does well" are you referring to fermentation performance or beer quality?

It is a reference to not throwing a lot of metabolic trash.  As we have learned, there are strains that do not throw a lot of metabolic trash beyond 75F. Basically, a brewer should pick a strain that will produce the desired result under his/her brewery conditions.  Far too many brewers attempt to trick a yeast strain into performing well under their brewery conditions.  Sure, it can be done, but it requires additional equipment such as a temperature-controlled fermentation chamber.  Unless one lives in area where it is ridiculously hot all of the time, the need for a temperature-controlled fermentation chamber can be eliminated by brewing with the seasons and using yeast cultures that perform well under specific seasonal temperatures.  A good example is Wit beer.  Wit beer was traditionally brewed in the warmer months. Hopefully, the "everything IPA" craze will end and brewers will start brewing with the seasons again (lagers during the cold winter months, ales in the fall and spring, and beers that have been traditionally fermented at warmer temperature like many Belgian styles in warm months). 
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: denny on September 20, 2020, 09:40:18 am
I brewed with the seasons for many years.  I now revel in the fact that I d0bbt have to do that and I can brew what I like when I like.  And that includes a LOT of IPA.
Title: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: BrewBama on September 21, 2020, 06:28:23 am
About the only seasonal brewing I do is darker beers for cooler weather. I like Browns, Porters, and Stouts in the cooler months.


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Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: tommymorris on September 21, 2020, 07:09:18 am
I revel in brewing only what I want also. It’s liberating. I pretty much brew light lagers (mostly Pils and Exports), American Ales (mostly APA but some Ambers and Browns), and an occasional English Pale. That’s pretty much it.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Richard on September 21, 2020, 08:57:50 am
I live in California and people say we don't have any seasons here, so brewing by the seasons would mean no brewing! It just wouldn't work for me. I don't have an inside space that gets cold enough for lagers in the winter, and I hate Belgian saisons so I wouldn't brew them in the summer. The Norwegian Kveik yeasts provide an interesting alternative to saisons for high-temperature summer fermenting.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 21, 2020, 06:46:56 pm
]Thanks Denny & Saccharomyces! I appreciate the clarification. I'm looking forward to issuing the SNS method for a lager!

Cheers,
Brandon

Sent from my Pixel 2 XL using Tapatalk

My first name is Mark.  Please feel free to use that name.  I had to change my user name from S. cerevisiae to Saccharomyces to spare the forum and AHA headquarters drama created by an ex-neighbor with whom my ex-wife and I were locked in a zoning dispute (my word of advice is that if a neighbor is using his/her property in a non-comforming way and your county does not have strong zoning enforcement, you need to move).
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: chezteth on September 21, 2020, 07:10:20 pm


My first name is Mark.  Please feel free to use that name.  I had to change my user name from S. cerevisiae to Saccharomyces to spare the forum and AHA headquarters drama created by an ex-neighbor with whom my ex-wife and I were locked in a zoning dispute (my word of advice is that if a neighbor is using his/her property in a non-comforming way and your county does not have strong zoning enforcement, you need to move).
[/quote]

Thanks Mark! I appreciate your extensive knowledge of yeast!
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: BaseWerks Brewing on September 23, 2020, 12:04:40 pm
Quote
Quote from: Saccharomyces on September 19, 2020, 12:35:32 PM
Quote from: denny on September 18, 2020, 10:13:55 PM
Mark, I have a question...lately I've been brewing 12 gal. batches on the Grainfather G70.  I split them into 2 fermenters, 6 gal. each.  Is there any chance that a 1 qt. SNS starter could be split be split between the 2?  Theoretically, do you think it would work?  I have no problem giving it a go if you think it might be feasable.

It should work for beers that are up to 1.060.   A lot of people used to pitch 500ml starters.  The only way to know for certain if it will achieve acceptable results for you is to try it.  I would be cautious with worts above 1.060, that is, unless you have access to an O2 bottle.  Higher osmotic pressure combined with increasing difficulty when it comes to dissolving O2 as gravity increases makes underpitching a risky endeavor.  High osmotic pressure leads to water being drawn out of the cells, which, in turn, causes a loss in turgor pressure.  Yeast cells without healthy cell walls and plasma membranes wrinkle and implode.

So your telling me the night before a brew day I can make a 1.5 qt starter in a 1 gallon jug, shake in up really well, pitch 1 packet of yeast, then mix it up a bit more before setting it on the counter.  The next day I can brew a 10 gallon batch of a moderate strength beer and just pitch that 1.5 qt (~1500ml) starter and I'll be good to go? No matter if its a ale or a lager? Here I'm making 3000ml starters with a stir plate days before and decanting down before pitching.   Consider my mind blown.

Anything else I need to be aware of?  Need to use 02 before pitching it into the beer?  Would this be the same for 2nd generation yeast that was harvested a few weeks/month ago and stored in the fridge?

I have the yeast book that is pretty common place with homebrewers.  I have notes from that describing if you let the starter sit past high krausen it allows the yeast to store up glycogen reserves and I was thinking that was a good thing.  Forgive me if that has already be explained but I start getting lost when it comes to microbiology.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Kevin on September 23, 2020, 12:40:36 pm


So your telling me the night before a brew day I can make a 1.5 qt starter in a 1 gallon jug, shake in up really well, pitch 1 packet of yeast, then mix it up a bit more before setting it on the counter.  The next day I can brew a 10 gallon batch of a moderate strength beer and just pitch that 1.5 qt (~1500ml) starter and I'll be good to go? No matter if its a ale or a lager? Here I'm making 3000ml starters with a stir plate days before and decanting down before pitching.   Consider my mind blown.

Anything else I need to be aware of?  Need to use 02 before pitching it into the beer?  Would this be the same for 2nd generation yeast that was harvested a few weeks/month ago and stored in the fridge?

I have the yeast book that is pretty common place with homebrewers.  I have notes from that describing if you let the starter sit past high krausen it allows the yeast to store up glycogen reserves and I was thinking that was a good thing.  Forgive me if that has already be explained but I start getting lost when it comes to microbiology.

I'm pretty sure you can make your SNS starter the morning of brew day. That's what I have been doing for the past couple years.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: denny on September 23, 2020, 01:47:54 pm


So your telling me the night before a brew day I can make a 1.5 qt starter in a 1 gallon jug, shake in up really well, pitch 1 packet of yeast, then mix it up a bit more before setting it on the counter.  The next day I can brew a 10 gallon batch of a moderate strength beer and just pitch that 1.5 qt (~1500ml) starter and I'll be good to go? No matter if its a ale or a lager? Here I'm making 3000ml starters with a stir plate days before and decanting down before pitching.   Consider my mind blown.

Anything else I need to be aware of?  Need to use 02 before pitching it into the beer?  Would this be the same for 2nd generation yeast that was harvested a few weeks/month ago and stored in the fridge?

I have the yeast book that is pretty common place with homebrewers.  I have notes from that describing if you let the starter sit past high krausen it allows the yeast to store up glycogen reserves and I was thinking that was a good thing.  Forgive me if that has already be explained but I start getting lost when it comes to microbiology.

I'm pretty sure you can make your SNS starter the morning of brew day. That's what I have been doing for the past couple years.

As long as it's at high krausen
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 23, 2020, 02:43:52 pm
So your telling me the night before a brew day I can make a 1.5 qt starter in a 1 gallon jug, shake in up really well, pitch 1 packet of yeast, then mix it up a bit more before setting it on the counter.  The next day I can brew a 10 gallon batch of a moderate strength beer and just pitch that 1.5 qt (~1500ml) starter and I'll be good to go? No matter if its a ale or a lager? Here I'm making 3000ml starters with a stir plate days before and decanting down before pitching.   Consider my mind blown.

Anything else I need to be aware of?  Need to use 02 before pitching it into the beer?  Would this be the same for 2nd generation yeast that was harvested a few weeks/month ago and stored in the fridge?

I have the yeast book that is pretty common place with homebrewers.  I have notes from that describing if you let the starter sit past high krausen it allows the yeast to store up glycogen reserves and I was thinking that was a good thing.  Forgive me if that has already be explained but I start getting lost when it comes to microbiology.

You cannot make a 1.5L SNS starter with a gallon jug because the container needs to be at least 4 times, preferably 5 times the volume of a the starter medium.  A 1.5L stater would require a minimum of a 6L bottle.  Additionally, there is literally no difference between a 1.5L and 1L starter (please throw your yeast calculator away).  The yeast cell count grows exponentially, not multiplicatively. The difference between a 1L and a 2L starter is one replication period.  Yeast cultures grow a rate of 2^N where, the symbol "^" denotes raised to the power of and N is the number of replication periods.  What this growth rate means to the layman is that cell count in the yeast biomass contains 1, 2, 4, 8, 16 ... times the initial cell count at time 0, end of replication period 1, end of replication period 2,  end of replication period 3, end of replication 4.   In effect, the cell count is doubling every replication period because a mother cell buds a daughter cell every replication period and a daughter cell that was budded during one replication period becomes a mother cell during the next replication period.

It is true that yeast cells store glycogen in preparation for quiescence, but they do so as a safeguard against starvation.  Yeast cells also undergo morphological changes in order to prepare for starvation that have to be undone before they can go about rebuilding ergosterol reserves, which are significantly more depleted if a culture is allowed to ferment beyond high krausen.  In effect, allowing a starter to ferment out results in longer lag times and higher initial O2 requirements.  You should read my blog, starting with "Yeast Cultures are Like Nuclear Weapons."  The URL is: https://www.experimentalbrew.com/blogs/saccharomyces (thanks goes to Denny and Drew for providing me a place to blog).  You need to double click the title of each blog entry to see the entire text.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: BaseWerks Brewing on September 23, 2020, 07:43:54 pm
Quote
You should read my blog, starting with "Yeast Cultures are Like Nuclear Weapons."  The URL is: https://www.experimentalbrew.com/blogs/saccharomyces (thanks goes to Denny and Drew for providing me a place to blog).  You need to double click the title of each blog entry to see the entire text.

Mark, will do.  I would already have read it but ran out of time while on my lunch break  :D
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: 4dogbrewer on September 24, 2020, 05:34:25 am
High krausen, how will I know when that happens? How long does it last? What do I do when I am past high krausen?
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: 4dogbrewer on September 24, 2020, 06:36:07 am
Making a starter on brew will be a challenge for me. Kind of busy with mashing and heating water. What about the night before brew day?
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: denny on September 24, 2020, 08:26:02 am
Making a starter on brew will be a challenge for me. Kind of busy with mashing and heating water. What about the night before brew day?

I do it 24 hours before.  I think that's optimal.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Richard on September 24, 2020, 10:22:25 am
Making a starter on brew will be a challenge for me. Kind of busy with mashing and heating water. What about the night before brew day?

As Mark said, you can start it earlier the day before and after a few hours you can put it in the refrigerator overnight. The cool temperature will slow the growth and effectively delay the onset of high krausen. I tried it this week and it worked great. I call this technique SNS The Next Generation: PICARD (Pitched In Container And Refrigerator Delayed).
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: narvin on September 24, 2020, 12:59:56 pm
Making a starter on brew will be a challenge for me. Kind of busy with mashing and heating water. What about the night before brew day?

As Mark said, you can start it earlier the day before and after a few hours you can put it in the refrigerator overnight. The cool temperature will slow the growth and effectively delay the onset of high krausen. I tried it this week and it worked great. I call this technique SNS The Next Generation: PICARD (Pitched In Container And Refrigerator Delayed).

And, when you have a newborn, you really don't know when you're going to brew.  I put it in the fridge for what ended up being 10 days and just decanted all the old liquid off of it.  With 2 minutes of pure O2 in the wort, it took off like a rocket!  What's old is new again, eh?
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: tommymorris on September 24, 2020, 01:48:27 pm
I call this technique SNS The Next Generation: PICARD (Pitched In Container And Refrigerator Delayed).
Nice!
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: BrewBama on September 24, 2020, 03:19:35 pm
I call this technique SNS The Next Generation: PICARD (Pitched In Container And Refrigerator Delayed).
Nice!



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Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Kevin on September 25, 2020, 08:03:39 am
Making a starter on brew will be a challenge for me. Kind of busy with mashing and heating water. What about the night before brew day?

Make it while the water is heating.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Wilbur on September 25, 2020, 10:28:04 am
Do you have any sources I can read that support your arguments against stir plates?

Here is a better question; namely, have you ever seen a stir plate mentioned in a published yeast research paper?  That is because a stir plate is not the correct device for cell culture.  The correct mechanical device is an orbital shaker.  That is what White Labs uses in the room where they grow seed cultures for propagation.   The use a stir plate in cell culture is an amateur brewer creation that is based on an incomplete understanding of brewing yeast strains.  As I mentioned in my blog entry, brewing yeast strains do not need to be stirred to remain in suspension because they belong to the NewFlo phenotype and the claim that they can exceed maximum cell density is nonsense. Brewing yeast strains do not truly respire in wort above the Crabtree threshold, which causes overflow metabolism.  What they do is shunt O2 and carbon from the fermentative metabolic pathway to the respirative metabolic pathway for the production of ergosterol and unsaturated fatty acids (UFA) during the lag phase, the spinning the culture continuously adds O2 to the culture is based on not only not understanding how brewing yeast strains operate, it is based on faulty information because very little O2 is entering the flask after CO2 production occurs due to CO2 being heavier than air.   About the only beneficial thing spinning does is help to drive off CO2 gas.  Other than that, the downsides of a stir plate outweigh the upsides.

As far as to references, I have pieced a lot information together from various publications I have read over the years.  I did not cherry pick my information.  I continuously check for new research.  If you use the search term "brewers yeast respiration Crabtree." you will be rewarded with links to many publications.   

Here is one such link:  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4429655/

The abstract from that publication.

"The capability to ferment sugars into ethanol is a key metabolic trait of yeasts. Crabtree-positive yeasts use fermentation even in the presence of oxygen, where they could, in principle, rely on the respiration pathway. This is surprising because fermentation has a much lower ATP yield than respiration (2 ATP vs. approximately 18 ATP per glucose). While genetic events in the evolution of the Crabtree effect have been identified, the selective advantages provided by this trait remain controversial. In this review we analyse explanations for the emergence of the Crabtree effect from an evolutionary and game-theoretical perspective. We argue that an increased rate of ATP production is likely the most important factor behind the emergence of the Crabtree effect."

Who ever made the claim that stir plates produce more yeast because they continuously aerate the culture knew nothing about how the Crabtree effect.

Quote
Isn't intense shaking also going to induce shear stress?

Yes, it will, which I noted in the blog entry.  As I mentioned, the starter can be pitched before or after shaking. If one pitches after shaking, it is best to gently shake the culture a second time to disperse the cells.

Quote
If you pitch the whole starter, then don't you usually pitch the early flocculating yeast anyway? Isn't pitching early flocculating yeast an issue with yeast cropping/sourcing?

I think that you are misreading into what I wrote or reading into it.  Both methods result in early flocculators.  The difference is that they are not held in suspension with an SNS starter.  The whole argument that a yeast culture needs to be spun to remain in suspension demonstrates a lack of understanding of the NewFlo phenotype (you can Google that one too).

Quote
The last I feel often gets confounded, I feel I often read complaints against a particular method in hobbies when the method is independent of the end result. Is the primary issue using a stir plate, or pitching a starter that's fermented out? I typically use a stir plate but start my starter an hour or two before the brew day. When I'm done brewing, the starter is usually at high krausen and I pitch the whole thing.

It is primarily an issue of stir plates being promoted as the best way to make starters to new brewers, which is not based on peer-reviewed science.  It is based on amateur brewer dogma just a like the dogma of using a secondary fermentation vessel to avoid autolysis.  Luckily, the use of secondary fermentation vessels has died off.  My goal is to educate new and exiting brewers about the fallacy of promoting stir plates as the best way to make a starter because it is not backed up by science. The absolute best way to make a starter is to saturate the starter wort with an O2 bottle and a diffusion stone before the culture is pitched (pure O2 provides for a higher saturation level than air). However, that method imposes cost and the responsibility of keeping a diffusion stone sanitary.  As mentioned in the blog entry, my method of making a starter is not do all, be all method for making a starter.  What it is is simple, low cost, and highly effective.  The proof is in the pudding that few of the people who have tried SNS after using a stir plate went back to using a stir plate.  Why would a brewer work harder than he/she needed to in order to achieve a comparable result?

By the way, I am not targeting you.  I expect to get heavy blow back from the blog entry.  People do not like to feel like they have been taken for a ride based on faulty information.

A few more posts since I last checked this out...

I think people should use whatever method works for them. I've done SNS and used a stirplate, and I tend to use my stirplate. I've got a newborn, so once it's started I don't have to swirl or do anything to release CO2 from solution. I think there's also a huge number of homebrewers who've successfully used a stirplate without creating a "foul smelling thing."

TLDR Version:


I'd also say it's unfair to say no testing or research has been done regarding starters at a homebrew level. Take a look at "Yeast" by Chris White & Jamil Zainasheff. Your claims of "foul smelling things" also fly against the experience of many homebrewers, who use stir plates without issues.

Carbon dioxide toxicity is something that is confirmed by science. This is commonly tested in a bioreactor, with oxygen continuously supplied. With this optimal setup, yeast growth and health is slightly inhibited when CO2 becomes greater than 40% of the solution, and significantly inhibited at concentrations above 50%. From data collected by Die_Beerery, you can see that yeast will consume 10 ppm of dissolved oxygen in an hour. It thus seems self evident that without regular agitation, yeast growth will be limited.

https://www.themodernbrewhouse.com/wort-study-1/ (https://www.themodernbrewhouse.com/wort-study-1/)
https://pubmed.ncbi.nlm.nih.gov/786407/ (https://pubmed.ncbi.nlm.nih.gov/786407/)

Quote
Our tests showed that vigorously shaking a starter every hour results in approximately double the number of cells created when using a starter that is not shaken.
Yeast Whit & Zainasheff

Quote
The yeast will do best when the starter setup continuously releases the carbon dioxide they reate, keeps them in suspension and evenly distributed throughout the solution, and provides them with access to reasonable amounts of oxygen.
Yeast White & Zainasheff

Carbon dioxide is heavier than air, but that's not relevant when there's moving fluid. It might factor in an environment like a cave where there's no air movement, but actively fermenting yeast puts out CO2. This would only limit oxygen intake if you have an airlock in place, or the positive pressure of carbon dioxide put off by the starter exceeds the atmostpheric pressure. High krausen is typically achieved in 12-18 hours (White & Zainasheff), and many beers see airlock activity in 4+ hours so I think it's safe to say that a starter will take up O2 from the atmosphere for a few hours after yeast is pitched.

Hopefully this was rambling and incoherent enough, I had to piece it together in between a dozen or so diaper changes.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: denny on September 25, 2020, 10:51:47 am
Since Chris White has been brought into this, I'll quote what he said to me when I told him about the SNS method....."that's great!  Homebrewers are too hung up on numbers"
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Wilbur on September 25, 2020, 11:02:31 am
Since Chris White has been brought into this, I'll quote what he said to me when I told him about the SNS method....."that's great!  Homebrewers are too hung up on numbers"
I agree, if you read his book and look at some of the stuff Escarpment and others have put out, it's pretty clear that yeast requirements are pretty broad. My only point was the idea that there's no precedent or authority suggesting the use of a stir plate isn't really true.

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Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 25, 2020, 11:54:34 am
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Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 25, 2020, 12:46:18 pm
@wilbur

I does appear that I have somehow slapped your proverbial puppy. I do not know if you are being obtuse or you are incapable of understanding what I have written because your counter argument is disjointed and your understanding of gas exchange and SNS is lacking. First off, nowhere  in the description of my method do I state that the starter needs to be shaken periodically. I challenge you to find any text where I make claim. Secondly, CO2 naturally comes out of solution at room temperature. Anyone who has pulled an over-gassed pint from a cold keg has experienced the massive foaming that occurs as CO2 gas rapidly comes out of solution. The only way to prevent out gassing at room temperature is via pressure.  A starter continues to outgas CO2 even when a airlock is attached.  However, nowhere in my method do I discuss using an air lock. I have always used a container that has a screw-on cap. All one has to do after shaking is loosen the cap.

As far to the use of an impeller in a bioreactor, that is not the way it is used in continuous propagation.  The impeller is not used as much to drive off CO2 as it is to keep the medium at a steady state (Google “steady state condition”). Yeast and spent medium are continuously drawn off on the discharge end while new medium and O2 are continuously added to the process on the intake end; therefore, CO2 has a way to escape solution.

In the end, no one in this thread has mentioned that you need to switch propagation methods, no one. This thread has been about the belief that stir plates are the best way to make starters being myth. On the other, you joined the discussion apparently itching for a fight. As I mentioned above, it is like I slapped your proverbial puppy when all I did was present facts that are backed up by peer-reviewed science, science that has stood the test of time and has been built upon by other professional scientists. I have been studying brewing yeast for a long time, seriously for at least a decade. I brewed almost exclusively with yeast I isolated and maintained on agar slants for my first and second passes through the hobby, which means I have a pretty good understanding of yeast management. I did not start out to prove that stir plate mania was myth.  It is just that as an INTJ (Myers-Briggs type), I have an insatiable thirst for knowledge. Brewing yeast has fascinated me for close to thirty years. The results that I achieved using a stir plate did not align with the hype, given my previous experience with other methods. That is what caused me to question the use of stir plates in the amateur brewing community.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 25, 2020, 01:03:43 pm
My only point was the idea that there's no precedent or authority suggesting the use of a stir plate isn't really true.

One last thing, there is zero precedent outside of the amateur brewing community for the use of stir plates, zero.  The problem with using amateur brewing as a president is inherent bias. When all one has ever used to make a starter is a stir plate outside of just pitching a culture into starter wort, one is working from a scientifically myopic point of view. Your insistence that agitation is need to release CO2 is a prime example of this phenomenon in brewing at the amateur level.  CO2 removal is not as critical as O2 in propagation and O2 pickup is a function of specific surface area, that is, when not using direct CO2 injection.
 
Maybe, it is because I survived having my research tested in graduate school (it was brutal), but my approach has been to continuously read new publications to see if previous research has been rendered obsolete by new research. I find that only a small proper subset of amateur brewers have this type mindset, most, but not all, have been with the hobby for a long time. These people are lifelong learners.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Wilbur on September 25, 2020, 01:39:03 pm
Hey bud, I'm not taking offense to anything. You posted an article, I'm engaging in discussion. Almost as if I was on a forum. I thought I'd add some constructive criticism, and you told me to Google things. So I did.

My knowledge of gas dynamics is pretty good. I do not claim that CO2 will not come out of solution. Some will, and some won't. My point is that above certain concentrations, CO2 will slow yeast growth. This is widely documented in scientific research.

My other point on CO2 is that it will not form a blanket if there is fluid/gas in motion. This motion occurs precisely because CO2 is off gassing. Until there is enough CO2 being produced by the yeast to produce a positive pressure effect, oxygen will continue to be present in the atmosphere in the starter. It seems self evident that there's not enough active yeast at pitch to create that condition. I don't care for myths either, so I didn't want to let the CO2 blanket myth stand.

I never claimed bio reactors had impellers. I'm not sure where that came from.

I think I've made it pretty clear that I don't have a problem with SNS or stir plates, and in the end I'm not drinking your beer anyway. I just like talking about brewing.

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Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 25, 2020, 03:28:23 pm
My other point on CO2 is that it will not form a blanket if there is fluid/gas in motion. This motion occurs precisely because CO2 is off gassing. Until there is enough CO2 being produced by the yeast to produce a positive pressure effect, oxygen will continue to be present in the atmosphere in the starter. It seems self evident that there's not enough active yeast at pitch to create that condition. I don't care for myths either, so I didn't want to let the CO2 blanket myth stand.

Please point to the post where I used the word "blanket."  I used the term "positive pressure."  As long as there is positive pressure from off-gasing, spinning a culture to aerate it during active fermentation is a stretch, especially in a cone, which concentrates the pressure of the escaping CO2 while minimizing the amount of specific surface area where O2 pickup can occur.  CO2 molecules are heavier than O2 molecules.  That is easy to see because CO2 contains a carbon atom in addition to oxygen atoms.  While O2 reaching the surface is possible while CO2 is being expelled, there will not be much of it.  It is law of partial pressures. Unless something is done to increase the pressure in the headspace of the propagation vessel, CO2 will continue to come out of solution.  The escaping CO2 will eventually diffuse, but it will remain in at a high enough level to make O2 ingress difficult because, once again, CO2 is heaver than O2.

The reality it that I would not have written the blog entry if I did not have my ducks in a row because I expected stir plate myth believers to come at me like a hungry pack of wolves.  It takes a lot of courage and solid set of facts to claim that the emperor has no clothes.  You claim to want to engage in constructive criticism, but what I see, and I sure others do, is someone who has taken an aggressive stance on shutting down the discussion.  Once again, if you are happy with your starter method, keep it.  However, I seriously doubt that you have tried my method because a) you would know that the culture is only shaken to introduce O2 one time and b) it is much simpler than using a stir plate. One cannot beat pouring boiled media into a sanitized jug, capping the jug with a sanitized screw-on cap, shaking the bejesus out of it, pitching a culture, putting screw-cap back on the jug, gently shaking the starter to disperse the cells, loosening the cap to allow CO2 gas to escape, waiting 12 to 18 hours, and then pitching the entire contents of the starter.  It is that simple and the results are repeatable. 

The reality is that I did not twist anyone's arm to switch from using a stir plate to using my method because I know that old habits die hard.  It is easy for a process or procedure to become ingrained.  I received a lot of push-back on this forum when I originally posted my method close six years ago.  People could not believe that something so simple and cheap could work as well as it does.  I left the hobby for a little under four years due to family issues.  What brought me back was that I was astonished to see how many people had adopted my method of making a starter world-wide, most of whom are not active in this forum.  I literally could not believe it.  That was when I realized that the hobby still had people with open minds.  Homebrewing dogma cripples our hobby. The stir plates produce superior cultures to all other methods myth is homebrewing dogma.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Wilbur on September 25, 2020, 03:45:18 pm
You're saying I'm aggressive but you cast doubts on if I've tried your method? Have a nice day sir, I am done.

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Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Kevin on September 26, 2020, 09:54:58 am
... I have always used a container that has a screw-on cap. All one has to do after shaking is loosen the cap

And don't forget this step. And by all means don't forget this step and then several hours later, when ready to pitch, swirl the contents before remembering to loosen the cap. Don't ask me how I know.  :-[
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: waltsmalt on September 28, 2020, 07:08:09 pm
Really want to give this method a shot with my next brew.  It’s a Belgian IPA, 1.059 OG, and a 10 gallon batch.  All of the beer will be fermented in a single fermentor.  So, if I’m reading this right, I should just: take two 1 gallon jugs, two yeast packets, and make a 1 quart starter.  Then I should just pitch both in the 10 gallon batch.  All done 24 hours or so prior to brewing.  Sound right?  Did I miss anything?
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: pete b on September 28, 2020, 07:16:18 pm
Really want to give this method a shot with my next brew.  It’s a Belgian IPA, 1.059 OG, and a 10 gallon batch.  All of the beer will be fermented in a single fermentor.  So, if I’m reading this right, I should just: take two 1 gallon jugs, two yeast packets, and make a 1 quart starter.  Then I should just pitch both in the 10 gallon batch.  All done 24 hours or so prior to brewing.  Sound right?  Did I miss anything?
Sounds right, assuming you mean two one quart starters, one for each gallon jug, it’s that simple. Really, the only tricky part is timing the high krausen with the time you are ready to pitch and there is definitely wiggle room. As with anything that involves living organisms you need to be prepared to be flexible and react to the critters timing. You are a steward not a master.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 28, 2020, 08:02:26 pm
Sounds right, assuming you mean two one quart starters, one for each gallon jug, it’s that simple. Really, the only tricky part is timing the high krausen with the time you are ready to pitch and there is definitely wiggle room. As with anything that involves living organisms you need to be prepared to be flexible and react to the critters timing. You are a steward not a master.

One thing I have learned from growing and maintaining a sourdough culture as well as making sourdough is that if a starter looks like it is going to crest too soon (e.g., the onset of low krausen), one can just place the starter in one's refrigerator (just remember to pull it out of the refrigerator at least an hour before pitching.  Fermentation will not stop.  It will just slow to a crawl.  The process is known as "retarding fermentation."  For example, a sourdough culture kept at room temperature needs to be fed every day.  However, if one feeds a mature sourdough culture and then places it in a refrigerator, the feeding interval can be pushed to at least five days.  I recommend retarded fermentation to another forum member who schedule made a 12 to 18 hour pitching interval too short.  It worked so well that he gave it another name. 
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Richard on September 28, 2020, 09:40:44 pm
I recommend retarded fermentation to another forum member who schedule made a 12 to 18 hour pitching interval too short.  It worked so well that he gave it another name.
Yeah, that was me. When I was trying to come up with a clever name my wife, who is a nurse, told me not to use the word "retarded". I used the phrase "refrigerator delayed" instead. I called it SNS The Next Generation: PICARD (Pitched In Container And Refrigerator Delayed).
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: pete b on September 29, 2020, 07:24:55 am
Is it accurate to say that refrigerating needs to happen at least just before high krausen at the latest?
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 29, 2020, 04:44:44 pm
Is it accurate to say that refrigerating needs to happen at least just before high krausen at the latest?

Yes, retarding the fermentation should occur before high krausen is reached.  Low krausen (when patches of foam start to appear on the surface) is about the latest that I would recommend retarding the fermentation. The reality is that different strains proceed at different paces.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: kpfoleyjr on September 30, 2020, 12:27:33 pm
I've been using a stir plate for a while, and want to try the SNS method.  I normally use Wyeast and brew 5 to 6-gallon batches.  I wanted to know what others think of this as a plan to follow.  Excuse the detail; i have Engineer disease.

1) Put about a liter (or whatever amount BeerSmith3 indicates, depending upon the age of the yeast packet) of boiled and cooled Briess Golden Light dry malt extract and RO water with a gravity of about 1.035 into a sanitized glass container.  This would typically be done the day before brewing.
2) Place a sanitized stopper on the container and shake it vigorously to aerate the starter wort.  (I used to add oxygen, but will not for the SNS).
3) Pitch the sanitized yeast packet into the wort while it's within the correct pitching temperature range.  Swirl the mixture to mix it thoroughly.
4) Use a sanitized airlock and stopper to close off the container.  Watch for the peak in bubbling at the airlock, and foam on top of the mixture, to determine when it's at high Krausen.
5) Replace the airlock with a piece of sanitized aluminum foil at high Krausen, and move the container to a 40 degree refrigerator to slow down the yeast action.
6) In a day or two, on brew day, remove the container from the refrigerator and allow the starter to rise to room temperature.
7) Add oxygen to the brewing wort.  Swirl the starter mixture to suspend the sediment on the bottom, then pitch the entire content into the brewing wort.

Anything incorrect in my thinking?  Anything missing?  Any step that could be made easier by eliminating something that's unnecessary?

Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Kevin on September 30, 2020, 01:06:04 pm
I've been using a stir plate for a while, and want to try the SNS method.  I normally use Wyeast and brew 5 to 6-gallon batches.  I wanted to know what others think of this as a plan to follow.  Excuse the detail; i have Engineer disease.

1) Put about a liter (or whatever amount BeerSmith3 indicates, depending upon the age of the yeast packet) of boiled and cooled Briess Golden Light dry malt extract and RO water with a gravity of about 1.035 into a sanitized glass container.  This would typically be done the day before brewing.
2) Place a sanitized stopper on the container and shake it vigorously to aerate the starter wort.  (I used to add oxygen, but will not for the SNS).
3) Pitch the sanitized yeast packet into the wort while it's within the correct pitching temperature range.  Swirl the mixture to mix it thoroughly.
4) Use a sanitized airlock and stopper to close off the container.  Watch for the peak in bubbling at the airlock, and foam on top of the mixture, to determine when it's at high Krausen.
5) Replace the airlock with a piece of sanitized aluminum foil at high Krausen, and move the container to a 40 degree refrigerator to slow down the yeast action.
6) In a day or two, on brew day, remove the container from the refrigerator and allow the starter to rise to room temperature.
7) Add oxygen to the brewing wort.  Swirl the starter mixture to suspend the sediment on the bottom, then pitch the entire content into the brewing wort.

Anything incorrect in my thinking?  Anything missing?  Any step that could be made easier by eliminating something that's unnecessary?

1) Forget what beersmith tells you about cell count. Just make enough starter medium so that it is 1/4 the volume of the vessel you are using.
2) Sounds good. 3) Sounds good.
4) Skip this. Just go right to #5 and cap the top with foil or an airlock.
6) A SNS starter will be ready well before a day or two unless you are talking about retarding the fermentation.
7) Yep. I've begun skipping the aeration part though unless I am making a high gravity beer.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: kpfoleyjr on September 30, 2020, 02:03:56 pm
Okay, but it seems like “high Krausen” was mentioned a lot in the other posts - I thought it was important to be there, but didn’t know a good way to determine when it was occurring.  I thought with the airlock, I could easily see when the peak in bubbling happened, and with the foam on top, know it was at high Krausen.  Knowing the peak of high Krausen is the only thing I’m still unsure of . . .


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Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on September 30, 2020, 03:18:11 pm
Okay, but it seems like “high Krausen” was mentioned a lot in the other posts - I thought it was important to be there, but didn’t know a good way to determine when it was occurring.  I thought with the airlock, I could easily see when the peak in bubbling happened, and with the foam on top, know it was at high Krausen.  Knowing the peak of high Krausen is the only thing I’m still unsure of . . .

High krausen is when the top of the starter media or wort becomes completely covered with a foam head.   Low krausen is when patches of foam appear on top the starter media or wort.  If you start to see low krausen appearing and you need more than a few hours to complete making a batch of wort, just stick the starter in a refrigerator.  If you are using a container with a screw-on lid, there is no need for a stopper and airlock.  All you need to do is loosen the lid after shaking and inoculating the starter wort.  Nothing is going to get into your starter because microflora does not crawl.  It rides on house dust.  In fact, I would recommend against filling an airlock on a starter.  You want as little resistance as possible to out-gassing.  Usually, an SNS starter will reach high krausen within 12 hours, sometimes sooner.  You want to pitch the starter no latter than six hours after high krausen has been reached for optimal performance, but different yeast cultures work at different rates; therefore, experience with a yeast culture and the method is the best teacher.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: kpfoleyjr on September 30, 2020, 09:18:57 pm
Thanks, I’ll do that and will probably use an Erlenmeyer flask with a foam stopper.  Looking forward to this and seeing how well it performs.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on October 01, 2020, 05:11:35 pm
Thanks, I’ll do that and will probably use an Erlenmeyer flask with a foam stopper.  Looking forward to this and seeing how well it performs.

Do you have access to a 5L Erlenmeyer flask?  It is not something that I would recommend due to the conical shape of an Erlenmeyer flask, but a 5L flask should do the trick.  You just need a solid stopper as well as need to hold the stopper tightly when shaking.  If you do not have 5L Erlenmeyer, you can forget about using it for SNS.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: tommymorris on October 01, 2020, 05:32:38 pm
My experience is that after shaking the starter like it owes me money a large head of foam appears immediately. That foam doesn’t subside before low or high krausen. As such, I can never tell how far a long the process actually is. So, I just wing it.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: kpfoleyjr on October 01, 2020, 05:55:30 pm
I do have a 5L Erlenmeyer flask, but after seeing your comment, I will use a 5L cylindrical glass Pyrex jug and stopper that I bought at a flea market for $2.  I’ve used it previously for larger starters.  Thanks for the follow-up tip.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Saccharomyces on October 02, 2020, 03:31:49 pm
A solid stopper is only needed during the shake.  I would put a piece of aluminum foil that has been sprayed with alcohol or sanitizer over the mount of the flask after the wort has been shaken and inoculated.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: Kevin on October 02, 2020, 09:05:15 pm
I do have a 5L Erlenmeyer flask, but after seeing your comment, I will use a 5L cylindrical glass Pyrex jug and stopper that I bought at a flea market for $2.  I’ve used it previously for larger starters.  Thanks for the follow-up tip.

Just buy a gallon jug of wine. Drink the wine. Use the jug for SNS starters.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: BaseWerks Brewing on December 03, 2020, 01:14:18 pm
If I'm doing a 10 gallon batch I need 2 quarts of starter, correct?  Would it be best to split the yeast packet between two one quart starters or make one two quart starter?  Do I need to increase it for a big beer?  1.10+ 
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: denny on December 03, 2020, 01:30:35 pm
If I'm doing a 10 gallon batch I need 2 quarts of starter, correct?  Would it be best to split the yeast packet between two one quart starters or make one two quart starter?  Do I need to increase it for a big beer?  1.10+

I have done 12 gal. of a 1.060ish beer by splitting a qt. between 2 6 gal. ferments
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: BaseWerks Brewing on December 03, 2020, 02:09:32 pm
Sweet, what do I need to do for bigger beers? Should I stick to 2 quarts for that?  I'm planning to brew a barleywine soon.
Title: Re: Shaken, not Stirred: The Stir Plate Myth Buster
Post by: denny on December 03, 2020, 02:19:46 pm
Sweet, what do I need to do for bigger beers? Should I stick to 2 quarts for that?  I'm planning to brew a barleywine soon.

In that case, I brew a lower gravity beer first and use the slurry from that.  I've done that from before the days of SNS.