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General Category => Yeast and Fermentation => Topic started by: charlie on December 09, 2019, 02:15:14 AM

Title: Do you have to have a stir plate? Not really.
Post by: charlie on December 09, 2019, 02:15:14 AM
Do you have to have a stir plate? Not really.

I'm a bit of a gear head. When I started all-grain brewing in 2009 I got any piece of gear that I thought I needed, which included three stir plates. I didn't really need three stir plates at the time because I was only running one 1 liter starter for 5 gallon batches. But it didn't take long until I upped my game to 10 gallon batches and two 1 liter starters.

My procedure was to pitch the yeast in the sanitized starter, put it on the stir plate, and wait until it finished out. This sometimes involved putting an aluminum pie pan under the flask to catch overflow from the too active starter.

At some point I started putting the starters on the stir plate for 6 hours until they became active, and then turning the stir plate off. At that point I would periodically swirl the flask manually until activity was subsiding, and then put it back on the stir plate until it was done.

These days I pitch the yeast in the starters, put them on the stir plate for one hour, and then swirl the flasks at about one hour intervals until activity subsides. I still put the starters on the stir plates when they are almost done, but I am no longer convinced that a stir plate is a necessary piece of equipment. Do they finish the starter faster? Yes. Are there any negatives to using a stir plate? Only if you object to cleaning up a mess on the bench where the starter krausened over.

I use mostly WLP-001, 007, 029 and Bell's House Yeast, and my experience has held true with these plus numerous others I have used over the years. If your experience is different I would like to know about it.

Note: I run 1L starters in 2L flasks, and 500 ml starters in 1L flasks. 2X volume is not enough to keep an active starter from kruasening over.

Charlie
Title: Re: Do you have to have a stir plate? Not really.
Post by: Robert on December 09, 2019, 05:20:13 AM
I use a well oversized flask (nominal  volume =/>2x actual starter volume) for the starter, and Fermcap.  The Fermcap is expended somewhere along the way, but there is still very little foam even at late stages.  I leave the stir plate running the whole time to keep gas exchange going -- getting CO2 out is beneficial even after O2 uptake is irrelevant  -- and to keep the yeast in suspension and in maximum contact with the medium.  I'm mostly a lager guy, so that may make a difference.  But I can't recall ever having problems with this protocol and ale yeast either.
Title: Re: Do you have to have a stir plate? Not really.
Post by: denny on December 09, 2019, 02:55:43 PM
I haven't used a stir plate in over 5 years.  I don't even know where mine is any more.  I've discovered it's unnecessary for me to use one.  And ya know what....it's made absolutely no difference in the quality of my beer.
Title: Re: Do you have to have a stir plate? Not really.
Post by: EnkAMania on December 09, 2019, 04:15:16 PM
I do vitality starter with 600-750 ml  wort 4-5 hours before pitching.  I use a stir plate, just because I have one and used to using it.  If I was to advise someone new, I would find something else to spend your money on first.
Title: Re: Do you have to have a stir plate? Not really.
Post by: Kevin on December 09, 2019, 04:49:14 PM
Once I read about the Shaken Not Stirred (SNS) method on this forum my stir plate has sat unused. It has been a year or more and as Denny says It has not made a difference in my beer.
Title: Re: Do you have to have a stir plate? Not really.
Post by: joe_meadmaker on December 09, 2019, 04:51:43 PM
I run 1L starters in 2L flasks, and 500 ml starters in 1L flasks. 2X volume is not enough to keep an active starter from kruasening over.

That's interesting.  My normal starter for a 5 gallon batch is a half gallon of liquid in a one gallon glass jug.  I don't recall ever having a blow-off with a starter.  I wonder if the shape of the flask could be part of the cause.  Being that the sides are angled rather than straight.

I normally use a stir plate for starters.  I occasionally use the SNS method, but I find it simpler to just put the starter on a stir plate rather than shaking it.  Both methods work perfectly fine as far as results are concerned.  Although I always use a stir plate for my big starters.  Most of the meads I make are 1/2 barrel batches.  For these I usually do a 2 gallon starter in a 3 gallon carboy.  It's really cool to see those turning on a Maelstrom.
Title: Re: Do you have to have a stir plate? Not really.
Post by: denny on December 09, 2019, 05:02:04 PM
Once I read about the Shaken Not Stirred (SNS) method on this forum my stir plate has sat unused. It has been a year or more and as Denny says It has not made a difference in my beer.

Kinda makes ya wonder why people still do anything else, huh?
Title: Re: Do you have to have a stir plate? Not really.
Post by: a10t2 on December 09, 2019, 05:21:04 PM
Kinda makes ya wonder why people still do anything else, huh?

Because it's a hobby and that's justification enough for wanting a new toy. ;)
Title: Re: Do you have to have a stir plate? Not really.
Post by: denny on December 09, 2019, 05:48:26 PM
Kinda makes ya wonder why people still do anything else, huh?

Because it's a hobby and that's justification enough for wanting a new toy. ;)

Yes, and the fact that it's a hobby also means you should think for yourself and try new things, even if they don't involve more equipment.
Title: Re: Do you have to have a stir plate? Not really.
Post by: dmtaylor on December 09, 2019, 07:09:34 PM
I've never used a stir plate, don't own one, and don't want one.  I try to use dried yeast as often as possible, and then starters are totally unnecessary.  And.... I'm a minimalist anyway.  Minimum equipment, minimum expenses, maximum shortcuts, that's me.  And I get away with it.  I recognize that this is not the norm.  But hell I'm still making pretty darn good beer... and mead, and cider.  Don't get me wrong... I do still tend to overthink a lot of topics... it's just, how to spend as much or more money than all my friends is NOT a goal of mine.  If I'm macho about anything, it's about how NOT macho I am.

:D
Title: Re: Do you have to have a stir plate? Not really.
Post by: Robert on December 09, 2019, 07:40:40 PM
Need for one aside, I'm curious about why Charlie gets all this foam-over.  One of the effects of a stir plate is to keep knocking froth down as it forms.  The one and only time I ever remember having a starter/propagation foam over was without a stir plate.   Just wondering. 

Title: Re: Do you have to have a stir plate? Not really.
Post by: denny on December 09, 2019, 08:33:36 PM
Need for one aside, I'm curious about why Charlie gets all this foam-over.  One of the effects of a stir plate is to keep knocking froth down as it forms.  The one and only time I ever remember having a starter/propagation foam over was without a stir plate.   Just wondering. 

Container too small?
Title: Re: Do you have to have a stir plate? Not really.
Post by: charlie on December 10, 2019, 08:40:33 PM
One of the effects of a stir plate is to keep knocking froth down as it forms.  The one and only time I ever remember having a starter/propagation foam over was without a stir plate.

I get exactly the opposite effect. I always figured that stirring causes the yeast to be more active and make more krausen. The starters are 100g of light dry DME diluted to 1L with tap water, so they're not high gravity.

The vessels are erlenmeyer flasks at 2X volume, i.e. a 2L flask for a 1L starter.

Charlie
Title: Re: Do you have to have a stir plate? Not really.
Post by: skyler on December 12, 2019, 12:41:44 AM
Between dry yeast and slurry, I rarely make starters anymore. When I do, I usually use a stir-plate because it saves time (especially with old/expired liquid yeast). That said, I use a stir-plate maybe once every 20 batches.
Title: Re: Do you have to have a stir plate? Not really.
Post by: denny on December 12, 2019, 03:29:44 PM
Between dry yeast and slurry, I rarely make starters anymore. When I do, I usually use a stir-plate because it saves time (especially with old/expired liquid yeast). That said, I use a stir-plate maybe once every 20 batches.

I'm curious about the time saving.  A SNS starter takes 24 hours.
Title: Re: Do you have to have a stir plate? Not really.
Post by: Barbarian Brewer on December 12, 2019, 08:33:32 PM
I usually put a starter on a stir plate the night before I brew because I can't shake or stir when I'm sleeping.  Once I'm up the next morning, I'll take it off the stir plate and begin the shaking and stirring.  So I guess my method is SP&SnS.  When I didn't put in on the stir plate overnight, and it just sat there for hours, I had a volcano with the first SnS in the morning.  It was fine after that.
Title: Re: Do you have to have a stir plate? Not really.
Post by: denny on December 12, 2019, 08:35:21 PM
I usually put a starter on a stir plate the night before I brew because I can't shake or stir when I'm sleeping.  Once I'm up the next morning, I'll take it off the stir plate and begin the shaking and stirring.  So I guess my method is SP&SnS.  When I didn't put in on the stir plate overnight, and it just sat there for hours, I had a volcano with the first SnS in the morning.  It was fine after that.

Shake before you start and there's no need for further shaking.
Title: Re: Do you have to have a stir plate? Not really.
Post by: riceral on December 12, 2019, 10:22:12 PM
Between dry yeast and slurry, I rarely make starters anymore. When I do, I usually use a stir-plate because it saves time (especially with old/expired liquid yeast). That said, I use a stir-plate maybe once every 20 batches.

I'm curious about the time saving.  A SNS starter takes 24 hours.

or less.
Title: Re: Do you have to have a stir plate? Not really.
Post by: charlie on December 13, 2019, 12:14:47 AM
I usually put a starter on a stir plate the night before I brew ...

I'm a fan of the crash and decant method.

I want my brews to start off at the exact post-boil gravity, so the first thing I do after flame-out is to put 1L of cooled wort in each decanted starter, and put them back on the stir plates. When I'm done futzing around with cooling and racking the wort into the fermentors then I oxygenate the wort and pitch the reconstituted starters. I usually have significant fermentation activity 3 or 4 hours later, so I'm going to stick with this system until something better comes along.

Charlie
Title: Re: Do you have to have a stir plate? Not really.
Post by: Stand on December 15, 2019, 01:16:28 PM
There might not typically be much of an advantage to a stir plate (which I use) because yeast we get now is so much better/healthier than in the bad ol' days, but is there some advantage to NOT using a stir-plate?  I made one out of a computer fan that cost me nothing and used it with a 64oz growler.

My understanding is that stir plates greatly increase the growth-rate of cells, and as I'm typically growing up cultures from frozen to 10 gallon batches it's something I'm worried about.
Title: Re: Do you have to have a stir plate? Not really.
Post by: ynotbrusum on December 15, 2019, 01:25:43 PM
There was a long thread on here a few years ago by a fellow named Mark (he went by the moniker “S. Cerevisae”.  Mark knew more about yeast than the rest of us and he advocated the Shaken not Stirred approach, because the yeast are pitched at their highest vitality point, which was more important than merely number of cells.  That has become accepted as a favorable approach, but the yeast are hardy critters and they will make beer with or without a stir plate or shaking vessel.  I like the SNS method when making a starter, but a stir plate clearly works, too.  However I prefer repitching slurry, frankly, when I have that option....
Title: Re: Do you have to have a stir plate? Not really.
Post by: denny on December 15, 2019, 02:27:26 PM
There might not typically be much of an advantage to a stir plate (which I use) because yeast we get now is so much better/healthier than in the bad ol' days, but is there some advantage to NOT using a stir-plate?  I made one out of a computer fan that cost me nothing and used it with a 64oz growler.

My understanding is that stir plates greatly increase the growth-rate of cells, and as I'm typically growing up cultures from frozen to 10 gallon batches it's something I'm worried about.

For me, the advantage of not using a stir plate is that it's faster and easier. 
Title: Re: Do you have to have a stir plate? Not really.
Post by: Stand on December 15, 2019, 08:40:49 PM
Mark knew more about yeast than the rest of us and he advocated the Shaken not Stirred approach, because the yeast are pitched at their highest vitality point, which was more important than merely number of cells. 

Would pitching at "highest vitality point" mean high krausen?  Would a stir-plate not also have that vitality point? Harder to see?

I'm still mostly cold-crashing and decanting.
Title: Re: Do you have to have a stir plate? Not really.
Post by: denny on December 15, 2019, 09:05:50 PM
Mark knew more about yeast than the rest of us and he advocated the Shaken not Stirred approach, because the yeast are pitched at their highest vitality point, which was more important than merely number of cells. 

Would pitching at "highest vitality point" mean high krausen?  Would a stir-plate not also have that vitality point? Harder to see?

I'm still mostly cold-crashing and decanting.

The beauty of SNS is that you don't have to crash and decant.  Believe me, I did that for at least 15 years and hundreds of batches, and once I tried SNS I couldn't believe how much time I'd wasted with crash and decant.
Title: Re: Do you have to have a stir plate? Not really.
Post by: Silver_Is_Money on December 16, 2019, 03:09:02 PM
I've never used a stir plate, don't own one, and don't want one.  I try to use dried yeast as often as possible, and then starters are totally unnecessary.  And.... I'm a minimalist anyway.  Minimum equipment, minimum expenses, maximum shortcuts, that's me.  And I get away with it.  I recognize that this is not the norm.  But hell I'm still making pretty darn good beer... and mead, and cider.  Don't get me wrong... I do still tend to overthink a lot of topics... it's just, how to spend as much or more money than all my friends is NOT a goal of mine.  If I'm macho about anything, it's about how NOT macho I am.

:D

The minimalist description as seen above very much defines my approach to brewing.  Being retired and on a fixed income with a relatively tight budget, and having returned to brewing only after a roughly 17 year brewing hiatus and only after retirement, modern brewing luxuries are not something high on my priority list.  I'm still making it essentially the way I did from the mid-late 80's to ~1998, but I make generally good beer overall, and occasionally I make really good beer.  There is admittedly the occasional loser, but I've never had a batch that I've needed to toss out (yet).  The most trouble I ever got myself into was when I attempted to brew and bottle a heavily dry hopped ~70 IBU IPA, and it rapidly oxidized and devolved into something several SRM shades darker than it was early on in the bottles, along with rapidly becoming less than desirable taste-wise.  That one came quite close to being tossed.  As long as I stick to older beer styles and don't mess with dry hopping, things mostly turn out decent via my old school methods.

I actually made my own stir plate from a desktop computer fan with (as I recall, hard drive sourced) magnets glued to it, and it worked well, and (being a pack-rat) I may still have it around somewhere, but I soon decided that it didn't improve anything related to my liquid yeast starters (which I try to avoid by mostly using dry yeasts), and (until today) I had forgotten all about it.
Title: Re: Do you have to have a stir plate? Not really.
Post by: a10t2 on December 16, 2019, 04:14:55 PM
There might not typically be much of an advantage to a stir plate (which I use) because yeast we get now is so much better/healthier than in the bad ol' days, but is there some advantage to NOT using a stir-plate?

The originating hypothesis for the SNS technique was that spinning the culture would induce enough shear stress to damage the cells. AFAIK there's no data available, at least not in the open literature (most large breweries use stirred propagators, so presumably there has been some work done).
Title: Re: Do you have to have a stir plate? Not really.
Post by: stpug on December 16, 2019, 05:19:26 PM
I use a variety of methods for providing sufficient yeast for an optimal fermentation.  Yeast propagation and revitalization methods I use are based on my yeast health, quantity on-hand, quantity needed, available time, desired effort, my current understanding of yeast knowledge and available tools in my toolbox with the ultimate goal of ensuring that my yeast handling process provides sufficient, healthy yeast for a fast start and complete fermentation with reasonably healthy yeast for cropping at the end of fermentation.  I'm far from perfect but I give it my best shot each and every time :D

There might not typically be much of an advantage to a stir plate (which I use) because yeast we get now is so much better/healthier than in the bad ol' days, but is there some advantage to NOT using a stir-plate?

The originating hypothesis for the SNS technique was that spinning the culture would induce enough shear stress to damage the cells. AFAIK there's no data available, at least not in the open literature (most large breweries use stirred propagators, so presumably there has been some work done).

Of the "large breweries" I've toured, most use orbital shakers (swirled propagators) which would indeed produce less shear forces than a spinning stir bar as well as having the effect of reducing yeast stress from carbon dioxide build-up.  For those that don't know the difference, it's more akin to swirling a flask using your hand as opposed to using a "blender-like" method.  Granted, a stir bar at very low speeds can have the result of (potentially acceptable) low shear forces while still keeping yeast well homogenized in the solution and helping to knock out carbon dioxide build-up (i.e. reducing yeast stress).

I haven't used a stir plate in over 5 years.  I don't even know where mine is any more.  I've discovered it's unnecessary for me to use one.  And ya know what....it's made absolutely no difference in the quality of my beer.

4 years (https://www.experimentalbrew.com/blogs/denny/old-dognew-tricks), but who's counting besides me  ;D
Title: Re: Do you have to have a stir plate? Not really.
Post by: hopfenundmalz on December 16, 2019, 06:31:01 PM
When Sean is talking large brewery, he means big. They probably have shake tables for intermediate steps, but there are propagators I've seen that are in the 20+ barrel size. Think Bell's, Sierra Nevada.

This shows how they mix.

https://www.alfalaval.com.au/media/stories/beverage-processing/brewing-a-better-yeast-propagation-process/

Title: Re: Do you have to have a stir plate? Not really.
Post by: denny on December 16, 2019, 06:38:28 PM
I use a variety of methods for providing sufficient yeast for an optimal fermentation.  Yeast propagation and revitalization methods I use are based on my yeast health, quantity on-hand, quantity needed, available time, desired effort, my current understanding of yeast knowledge and available tools in my toolbox with the ultimate goal of ensuring that my yeast handling process provides sufficient, healthy yeast for a fast start and complete fermentation with reasonably healthy yeast for cropping at the end of fermentation.  I'm far from perfect but I give it my best shot each and every time :D

There might not typically be much of an advantage to a stir plate (which I use) because yeast we get now is so much better/healthier than in the bad ol' days, but is there some advantage to NOT using a stir-plate?

The originating hypothesis for the SNS technique was that spinning the culture would induce enough shear stress to damage the cells. AFAIK there's no data available, at least not in the open literature (most large breweries use stirred propagators, so presumably there has been some work done).

Of the "large breweries" I've toured, most use orbital shakers (swirled propagators) which would indeed produce less shear forces than a spinning stir bar as well as having the effect of reducing yeast stress from carbon dioxide build-up.  For those that don't know the difference, it's more akin to swirling a flask using your hand as opposed to using a "blender-like" method.  Granted, a stir bar at very low speeds can have the result of (potentially acceptable) low shear forces while still keeping yeast well homogenized in the solution and helping to knock out carbon dioxide build-up (i.e. reducing yeast stress).

I haven't used a stir plate in over 5 years.  I don't even know where mine is any more.  I've discovered it's unnecessary for me to use one.  And ya know what....it's made absolutely no difference in the quality of my beer.

4 years (https://www.experimentalbrew.com/blogs/denny/old-dognew-tricks), but who's counting besides me  ;D

Time flies!  Thanks for the correction.
Title: Re: Do you have to have a stir plate? Not really.
Post by: denny on December 16, 2019, 06:39:36 PM
There might not typically be much of an advantage to a stir plate (which I use) because yeast we get now is so much better/healthier than in the bad ol' days, but is there some advantage to NOT using a stir-plate?

The originating hypothesis for the SNS technique was that spinning the culture would induce enough shear stress to damage the cells. AFAIK there's no data available, at least not in the open literature (most large breweries use stirred propagators, so presumably there has been some work done).

While there may or may not be an advantage in that respect the fact that it's faster, easier, and as effective is what sold me.
Title: Re: Do you have to have a stir plate? Not really.
Post by: Stand on December 17, 2019, 12:20:05 AM
Shear-force seems like a good theory, but is there any evidence to support the impact of this?  This really needs some experimentation, but my guess is that it wouldn't make much difference at all.

Yeast seems like a hearty little organism, so I'm sure all of these methods make great beer.  My issue is that I grow up yeast stocks from frozen 50ML vials, so growth is a real concern for me.  I've never had any problems at all with my methods which are based on the growth charts here: http://www.brewunited.com/yeast_calculator.php

Cheers!
Title: Re: Do you have to have a stir plate? Not really.
Post by: Wilbur on January 31, 2020, 05:26:10 PM
Personally, I keep forgetting to swirl, and eventually it foams up when I do. I don't see why a stir plate is incompatible to the SNS method. Isn't it really more about pitching yeast while active?

I start a few hours before I brew and start it on the stir plate. When it's time to pitch, I pitch 1/2-3/4 of my starter and let the rest finish out. The extra hours into a jar or two until the next brew day.

Sent from my Pixel 2 XL using Tapatalk

Title: Re: Do you have to have a stir plate? Not really.
Post by: majorvices on February 01, 2020, 05:14:40 PM
Late to the party here: I sometimes use a stir plate, sometimes don't. For lagers I always do (or use slurry). What I do use is half gallon/2L mason jars with these fermentation lids

(https://images-na.ssl-images-amazon.com/images/I/41ectbI-snL._AC_.jpg)

I don't tighten them down all the way until the starter is finished. They work great! And the jars way easier to clean and way cheaper than flasks.
Title: Re: Do you have to have a stir plate? Not really.
Post by: purduekenn on February 10, 2020, 01:52:56 PM
No more traditional yeast starters for me! Now using SNS vitality starters.
Title: Re: Do you have to have a stir plate? Not really.
Post by: TXFlyGuy on February 12, 2020, 12:43:54 PM
I haven't used a stir plate in over 5 years.  I don't even know where mine is any more.  I've discovered it's unnecessary for me to use one.  And ya know what....it's made absolutely no difference in the quality of my beer.

Never used one, never needed one, never will use one.
For a starter, a one gallon jug containing harvested yeast, mixed with some fresh sterile wort, and agitated to wake up the dormant cells, is all we ever used.

Shaken, not stirred.