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General Category => Yeast and Fermentation => Topic started by: Pi on September 23, 2015, 03:00:21 PM

Title: building a large starter
Post by: Pi on September 23, 2015, 03:00:21 PM
Got a vial of WLP830 and i am making a 5l starter for a Vienna brewing this sunday. I want to make another 5l starter for a similar batch i'm doing a couple days later, but was wondering what the best way to grow. Should i decant the first starter and dump another 5l of wort on that cake then split that between the 2 batches, or pinch a little cake from the first starter and start anew?
Title: Re: building a large starter
Post by: kramerog on September 23, 2015, 03:48:23 PM
I vote for "pinching." In the first option, 5 L + 5 L does not equal to 10 L.
Title: Re: building a large starter
Post by: narcout on September 23, 2015, 05:02:23 PM
Assuming you hit maximum cell density on your first 5L starter, I don't think you are going to grow more yeast by decanting into a second 5L starter.



Title: Re: building a large starter
Post by: S. cerevisiae on September 23, 2015, 08:58:01 PM
The better question is why do you believe that you need a 5L starter?   Are you making a large batch of beer?
Title: Re: building a large starter
Post by: Pi on September 24, 2015, 12:27:43 AM
The better question is why do you believe that you need a 5L starter?   Are you making a large batch of beer?
Cuz Mr Malty said so. 5.6 Gallons of 1.052 recommends 5l using a stir plate/1 vial. Last  Lager i did suffered i think because I under pitched.
First time a lesson, second time's a fool.
Title: Re: building a large starter
Post by: S. cerevisiae on September 24, 2015, 01:14:49 AM
That's beyond ridiculous.   No 5.6-gallon batch on the planet needs a 5L starter.  A batch of that gravity and size is a 1-liter starter pitched at high krausen at best.  I can start 5.6-gallon batch with 60B cells and produce an off-flavor-free beer.  Do you aerate your wort?  At what temperature do you start your wort?   
Title: Re: building a large starter
Post by: reverseapachemaster on September 24, 2015, 03:19:28 PM
What settings did you use to get to a 5l starter? The only way on a 5.6gal 1052 beer with that calculator is using a fairly old lager pack. Mrmalty IMO overshoots the viability drop off on yeast vials/packs. It also doesn't take into consideration whether you are aerating/oxygenating the wort or whether you are pitching at high krausen.
Title: Re: building a large starter
Post by: Wort-H.O.G. on September 24, 2015, 04:38:17 PM
i'd feel good with doing the 5l starter and split the cake for the two batches. good fresh yeast and plenty for both average size brews IMO.
Title: Re: building a large starter
Post by: jtoots on September 24, 2015, 06:11:40 PM
What settings did you use to get to a 5l starter? The only way on a 5.6gal 1052 beer with that calculator is using a fairly old lager pack. Mrmalty IMO overshoots the viability drop off on yeast vials/packs. It also doesn't take into consideration whether you are aerating/oxygenating the wort or whether you are pitching at high krausen.

I'm seeing the same results with a production date of today and continuous aeration. 
Title: Re: building a large starter
Post by: 69franx on September 24, 2015, 06:27:03 PM
When I plug 5.6g of 1.052 and 9/24 as production date, I get suggestion of 1 vial and 1.03L starter, unless I missed a detail somewhere...?
edit: missed lager, now it reads 2.06L
Title: Re: building a large starter
Post by: jtoots on September 24, 2015, 06:51:00 PM
When I plug 5.6g of 1.052 and 9/24 as production date, I get suggestion of 1 vial and 1.03L starter, unless I missed a detail somewhere...?
edit: missed lager, now it reads 2.06L
I get the same 2.06L when I'm at ale, simple starter.  When I swap it over to lager, it goes to 4.12 L with 2 vials.  That or 10.21L with 1 vial!  (keeping it at simple starter throughout).
Title: Re: building a large starter
Post by: 69franx on September 24, 2015, 06:55:19 PM
When I plug 5.6g of 1.052 and 9/24 as production date, I get suggestion of 1 vial and 1.03L starter, unless I missed a detail somewhere...?
edit: missed lager, now it reads 2.06L
I get the same 2.06L when I'm at ale, simple starter.  When I swap it over to lager, it goes to 4.12 L with 2 vials.  That or 10.21L with 1 vial!  (keeping it at simple starter throughout).

I see that now too, thought we were on continuous aeration. Simple does give 4.12L. I knew I must have been missing something, turns out it was 2 things
Title: Re: building a large starter
Post by: klickitat jim on September 24, 2015, 07:10:32 PM
I gave up on pitch calculators. Too many variables to consider. I don't poopoo them for an entirely new brew or yeast, but I have found that I usually need to tweak things on the following rebrews.

I've also quit using my stirplates, but thats because I am following the new trend of not following old trends.
Title: Re: building a large starter
Post by: 69franx on September 24, 2015, 07:13:21 PM
Right there with you Jim. No more stirred starters for me, and just trying to get within 1 replication period of optimal pitching rate. I have been very happy with my results so far 8)
Title: Re: building a large starter
Post by: klickitat jim on September 24, 2015, 07:28:42 PM
I don't shake it like it owes me money... thats what I wasted money on Oxygen and a stone for. So I oxygenate, then shake till I'm bored of shaking (about 15 secobds). Anyway, it gets me more yeast than the stirplate and it smells totally fresh and tastey, as compared to rank yeasty stirplate stuff. Works for me.

All of my ales get 2L of 1.030 and one smack pack per 6 gallons, lagers get two of those per 6 gallon. Amounts subject to change when dialing in a specific recipe. Someone may say thats too much, and I would say yes it might be. But the effects of too much are far less noticeable vs too little. Though, one might want too little or too much (at least compared to a calculator) depending on desired effects.
Title: Re: building a large starter
Post by: S. cerevisiae on September 24, 2015, 09:17:49 PM
Yeast calculators are about as useful as toilet paper when it comes to propagating yeast cells.  Yeast cells are living organisms that behave differently in different environments.  The only way to know how a yeast culture is going to behave in one's brewery is to use it and take very good notes.

As I have said many times, the difference between a 1L starter and a 2L starter is approximately 90 minutes of propagation time, making the argument for a 2L starter when pitching normal gravity beer a non-sequitur.  Now, the difference between a 1L starter and a 5L starter is log(5) / log(2)  * 90 = 208 minutes, or 3.5 hours of propagation time.  However, one is looking a step rate of 22 / 5 = 4.4 when pitching the cells from a 5L starter into a 22L batch of wort.  It takes approximately log(4.4) / log(2) = 2.14 replication periods to reach maximum cell density when pitching at that rate.   In practice, we should step between 10 and 20 for most batches, especially if we plan to repitch the slurry.  Pitching at a higher rate than that tends to lead to declining culture health, as the average cell age increases with each pitch.

The key to successful fermentation is to pitch enough healthy cells at the peak of their performance into well-aerated wort to get the job done.  The osmotic pressure difference between the cell contents and 1.056 wort is not high enough to cause dehydration and loss of turgor pressure, resulting in cell shrinkage and wrinkling of the cell plasma membrane as happens when one pitches a starter into 1.080 wort.  Additionally, the solubility of O2 decreases as wort gravity increases (Henry's Law).  In essence, we have to pitch a higher number of cells when pitching high gravity wort because of cell loss coupled with lower growth rates and cell health due to lower gas (O2) solubility.

Title: Re: building a large starter
Post by: klickitat jim on September 25, 2015, 12:02:56 AM
Yeast calculators are about as useful as toilet paper when it comes to propagating yeast cells.  Yeast cells are living organisms that behave differently in different environments.  The only way to know how a yeast culture is going to behave in one's brewery is to use it and take very good notes.

As I have said many times, the difference between a 1L starter and a 2L starter is approximately 90 minutes of propagation time, making the argument for a 2L starter when pitching normal gravity beer a non-sequitur.  Now, the difference between a 1L starter and a 5L starter is log(5) / log(2)  * 90 = 208 minutes, or 3.5 hours of propagation time.  However, one is looking a step rate of 22 / 5 = 4.4 when pitching the cells from a 5L starter into a 22L batch of wort.  It takes approximately log(4.4) / log(2) = 2.14 replication periods to reach maximum cell density when pitching at that rate.   In practice, we should step between 10 and 20 for most batches, especially if we plan to repitch the slurry.  Pitching at a higher rate than that tends to lead to declining culture health, as the average cell age increases with each pitch.

The key to successful fermentation is to pitch enough healthy cells at the peak of their performance into well-aerated wort to get the job done.  The osmotic pressure difference between the cell contents and 1.056 wort is not high enough to cause dehydration and loss of turgor pressure, resulting in cell shrinkage and wrinkling of the cell plasma membrane as happens when one pitches a starter into 1.080 wort.  Additionally, the solubility of O2 decreases as wort gravity increases (Henry's Law).  In essence, we have to pitch a higher number of cells when pitching high gravity wort because of cell loss coupled with lower growth rates and cell health due to lower gas (O2) solubility.
You lose me easily and frequently but that high gravity explanation is awesome. I did not know that. I knew it took more yeast, now I understand why.
Title: Re: building a large starter
Post by: Pi on September 25, 2015, 09:53:30 PM
Allow me to clarify:
Using Mr Malty,for 5.5 gallons of a 1.052 lager and 1 vial of WLP830 manufactured 8/28/15, Jamil's calculator recommends building 4.97 Liters of 1.030 starter.  400 billion cell count.
To be clear i am not planning on dumping the full 5 liters into my wort! The Starter fermented out in about 24hrs and is resting comfortably at 45* settling out. Sunday afternoon I'll decant and pitch the cake along with about.3l spent wort.
Now I'm no expert but I've been brewing lagers for roughly 9 years. And when i wing it and underpitch (ie. a 1 liter starter) Yeast gets stressed, my lagers come out sweet and under-attenuated. Conversely, When i use relatively fresh yeast, build a starter following Mr Malty's guidelines aerate, pitch low and come up to fermentation temp, I get very clean lagers.  I cant argue the explaination below. after reading it several times, walking away, then reading several more times it does make sense. I also know what works for me and what dont. Guess I'm just stupid
Title: Re: building a large starter
Post by: S. cerevisiae on September 25, 2015, 11:05:12 PM
A big part of your problem is that you are letting the starter ferment out.  One should never let a starter ferment out.  That's a no-no when propagating yeast.   A starter is not a small batch of beer.  It is a propagation medium, and should be treated as such. 

If you pitch at high krausen, you can can cut your cell count in half because the cells are still in the exponential phase with non-depleted ergosterol and unsaturated fatty acid (UFA) reserves.  Allowing a starter to ferment beyond high krausen results in unnecessary ergosterol and unsaturated fatty acid (UFA) depletion because all reproduction beyond that point is for replacement only and mother cells share their ergosterol and UFA reserves with all of their daughters.  It also results in the yeast cells undergoing survival-related morphological changes that have to be reversed before the cells can start to take in nutrients and expel waste products through their cell walls.  Quiescent cells place a higher initial O2 load on the wort.


Do you happen to be using a stir plate?    If so, that is part of your problem.  Stir plates subject yeast cells to shear stress.

Title: Re: building a large starter
Post by: Pi on September 28, 2015, 04:03:31 PM
I do not understand a lot of the technical specifics, but after much thought I must agree. It makes sense that after you grow a bunch of yeast, then they go back to sleep, then wake them back up...
So, in the future, I will try growing 1l of 1.030, and pitch the whole liter at high krausen/no stir plate. What temp. do you recommend for a lager starter?
Title: Re: building a large starter
Post by: klickitat jim on September 28, 2015, 04:12:56 PM
I do not understand a lot of the technical specifics, but after much thought I must agree. It makes sense that after you grow a bunch of yeast, then they go back to sleep, then wake them back up...
So, in the future, I will try growing 1l of 1.030, and pitch the whole liter at high krausen/no stir plate. What temp. do you recommend for a lager starter?
I want to know what Mark says about lager starter temp. But if he didn't say, my thinking is that i would do my lager starter at lager temp, because i wouldnt be decanting. It is probably going to take a little longer to reach high krausen at 50 vs room temp. I also worry about having enough, so I would either pitch two 1L starters or two smack packs into 2L shaken not stired, for my 6 gallon batches.
Title: Re: building a large starter
Post by: Pi on September 28, 2015, 04:18:22 PM

[/quote]
 I also worry about having enough, so I would either pitch two 1L starters or two smack packs into 2L shaken not stired, for my 6 gallon batches.
[/quote]
 Think I could split one WL vial between 2 1l?
Title: Re: building a large starter
Post by: smokeymcb on September 28, 2015, 04:19:03 PM
I do not understand a lot of the technical specifics, but after much thought I must agree. It makes sense that after you grow a bunch of yeast, then they go back to sleep, then wake them back up...
So, in the future, I will try growing 1l of 1.030, and pitch the whole liter at high krausen/no stir plate. What temp. do you recommend for a lager starter?
I want to know what Mark says about lager starter temp. But if he didn't say, my thinking is that i would do my lager starter at lager temp, because i wouldnt be decanting. It is probably going to take a little longer to reach high krausen at 50 vs room temp. I also worry about having enough, so I would either pitch two 1L starters or two smack packs into 2L shaken not stired, for my 6 gallon batches.

Sixty degrees  Fahrenheit is way too cold for a starter.  That's why your starters are taking forever to reach high krausen.   Starters should be incubated at 25C/77F (i.e., room temperature), regardless of yeast species (ale and lager yeast strains are different yeast species).  The goal of a starter is to increase yeast biomass, not make beer.
Title: Re: building a large starter
Post by: 69franx on September 28, 2015, 04:24:15 PM

I also worry about having enough, so I would either pitch two 1L starters or two smack packs into 2L shaken not stired, for my 6 gallon batches.
[/quote]
 Think I could split one WL vial between 2 1l?
[/quote]

This is what I have been doing and having good results with it. Not to say its correct or proper form, but its working for me
Title: Re: building a large starter
Post by: Werks21 on October 01, 2015, 07:17:11 PM
A big part of your problem is that you are letting the starter ferment out.  One should never let a starter ferment out.  That's a no-no when propagating yeast.   A starter is not a small batch of beer.  It is a propagation medium, and should be treated as such. 

If you pitch at high krausen, you can can cut your cell count in half because the cells are still in the exponential phase with non-depleted ergosterol and unsaturated fatty acid (UFA) reserves.  Allowing a starter to ferment beyond high krausen results in unnecessary ergosterol and unsaturated fatty acid (UFA) depletion because all reproduction beyond that point is for replacement only and mother cells share their ergosterol and UFA reserves with all of their daughters.  It also results in the yeast cells undergoing survival-related morphological changes that have to be reversed before the cells can start to take in nutrients and expel waste products through their cell walls.  Quiescent cells place a higher initial O2 load on the wort.


Do you happen to be using a stir plate?    If so, that is part of your problem.  Stir plates subject yeast cells to shear stress.

What is the best/easiest/most reliable way to determine high krasuen in a small starter? starters are hard to read. (for me anyway)
Title: Re: building a large starter
Post by: a10t2 on October 01, 2015, 08:04:57 PM
Got a vial of WLP830 and i am making a 5l starter for a Vienna brewing this sunday. I want to make another 5l starter for a similar batch i'm doing a couple days later, but was wondering what the best way to grow. Should i decant the first starter and dump another 5l of wort on that cake then split that between the 2 batches, or pinch a little cake from the first starter and start anew?

In my experience, stirred 8°P starters grow 100-150 billion cells per liter of medium. So you should be somewhere in the vicinity of double your target cell density, and I would think you could safely split the slurry in half to pitch both batches.

On the other hand, if pitching substantially more than that is giving you the results you want, by all means keep doing that. In that case my vote would be for "pinching".
Title: Re: building a large starter
Post by: S. cerevisiae on October 01, 2015, 08:26:54 PM
What is the best/easiest/most reliable way to determine high krasuen in a small starter? starters are hard to read. (for me anyway)

Usually, but not always, lack of a krausen is a sign that a starter was underaerated or there was too little or far too much carbon (extract).  However, in those cases, the end of the exponential phase should look like low krausen on a normal fermentation.  There will be very thin layer of foam, often only in patches, covering the surface of the starter.  High krausen on a normal healthy 1L or larger starter should produce a krausen that is at least 1/4" thick (I have had krausens on starters that were over 1" thick).  Experience is the best teacher with strains that do not produce much of a head.  One should always try to be in a situation where one can periodically monitor the progress of a starter (or a have a camera that can record what is happening during incubation).  As always, anything that happened during incubation that did get not recorded digitally or on paper did not occur.  A brewing log is a brewer's best friend.
Title: Re: building a large starter
Post by: brewinhard on October 01, 2015, 09:54:21 PM
Mark,

Regarding lager starters I know you mentioned that they should be completed around 75F to increase cell biomass.  If one wanted to pitch that starter at high krausen into a cooled 50F wort couldn't the yeast experience some sort of shock due to the more than 20F temperature difference?  If so, what do you recommend in this situation?
Title: Re: building a large starter
Post by: S. cerevisiae on October 02, 2015, 04:59:58 PM
The reason I made that comment is because incubation at low temperatures slows metabolism, and anything that slows metabolism slows replication.  I made the comment when I noticed that people were placing their starters in fermentation chambers.

With that said, I do not see a problem with lowering the culture temperature to pitching temperature before pitching it into a batch of wort.  Placing a culture in a refrigerator set to 50F is not going to drop the temperature of the culture in a second or two, which is what happens when we pitch a culture at 75F into 50F wort.   Let's put things in human terms.  If we walk into a refrigerator set to 50F, we will not experience an internal temperature drop as fast as if we were thrown into a large body of 50F water.

Title: Re: building a large starter
Post by: Werks21 on October 04, 2015, 01:26:47 AM
Usually, but not always, lack of a krausen is a sign that a starter was underaerated or there was too little or far too much carbon (extract).  However, in those cases, the end of the exponential phase should look like low krausen on a normal fermentation.  There will be very thin layer of foam, often only in patches, covering the surface of the starter.  High krausen on a normal healthy 1L or larger starter should produce a krausen that is at least 1/4" thick (I have had krausens on starters that were over 1" thick).  Experience is the best teacher with strains that do not produce much of a head.  One should always try to be in a situation where one can periodically monitor the progress of a starter (or a have a camera that can record what is happening during incubation).  As always, anything that happened during incubation that did get not recorded digitally or on paper did not occur.  A brewing log is a brewer's best friend.

Thanks, And that bit about the brewing log is spot on. I didn't record any real data on my fermentations for a while after I started brewing and now I'm kicking myself. I'm all over it now though.