Author Topic: Yeast cell count...Starters...Gravity range  (Read 1781 times)

Offline roguejim

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Yeast cell count...Starters...Gravity range
« on: March 25, 2012, 02:03:44 PM »
I've been doing some reading at mrmalty.com, and am left with some questions.

Assuming the info below is correct, what upper limit of wort SG's would you feel comfortable pitching a 2 liter starter into?  If a deviation of 20% is allowable per Logsdon, I'm coming up with upper wort gravity of about 1.064.  I realize Logsdon's statement is one of "preference". 


    1 liter starter = about 150 billion cells
    2 liter starter = about 200 billion cells
    1 liter starter, then pitched into 4 liter starter = 400 billion cells


The proper amount of yeast for 5.25 US gallons of 1.060 wort is around 225 billion cells if you are pitching 0.75 million per milliliter.
(750,000) X (20,000) X (15) = 225,000,000,000

"Logsdon says, "I try to stay within 20% of my ideal pitch rate and I prefer to slightly under pitch rather than over pitch."

Offline thcipriani

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Re: Yeast cell count...Starters...Gravity range
« Reply #1 on: March 26, 2012, 07:20:04 AM »
Assuming the info below is correct, what upper limit of wort SG's would you feel comfortable pitching a 2 liter starter into?

Too many variables.

I pitch some styles lower than others and some styles much higher than others. I grow much more than 200e9 in a 2L starter.

If you don't have a way to do cell counts or don't trust a sedimented cell volume then the Mr. Malty calculator is your best bet.
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Offline denny

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Re: Yeast cell count...Starters...Gravity range
« Reply #2 on: March 26, 2012, 08:01:59 AM »
I have no way to exactly quantify how many cells I pitch so I go strictly by volume, tempered by experience.  In general, I'll do a 2 qt. starter up to about 1.060 and 3 qt. for up to maybe the mid 80s.  Exactly on the numbers?  I doubt it.  But my experience is that it's close enough.
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Offline DrewG

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Re: Yeast cell count...Starters...Gravity range
« Reply #3 on: March 26, 2012, 09:08:48 AM »
Denny, for your 2 qt starters do you chill and decant or just pitch it all?
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Offline hopfenundmalz

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Re: Yeast cell count...Starters...Gravity range
« Reply #4 on: March 26, 2012, 09:21:47 AM »
Denny can answer how he does it, this is my $0.02.

I have been chilling my starters for some time, decanting and pitching the yeast slurry. Now the same is done for ales.

If you make a lager you have a huge starter, and it is a big fraction of the beer that is not like the beer you are brewing.  Heck 2 liters for a 5 gallon batch of ale is 10%.  If you spend time figuring out the OG and IBU, why have that go out of whack with 10% starter (unless you use that in the calculation - I never did).
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Offline denny

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Re: Yeast cell count...Starters...Gravity range
« Reply #5 on: March 26, 2012, 09:27:49 AM »
Denny, for your 2 qt starters do you chill and decant or just pitch it all?

I always chill and decant.  After tasting the spent starter wort, I have no desire to have that stuff in my beer.
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Offline hopfenundmalz

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Re: Yeast cell count...Starters...Gravity range
« Reply #6 on: March 26, 2012, 09:37:43 AM »
One more thing, the pros pitch slurry, at least in my experience.
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Offline a10t2

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Re: Yeast cell count...Starters...Gravity range
« Reply #7 on: March 26, 2012, 10:00:26 AM »
"Logsdon says, "I try to stay within 20% of my ideal pitch rate and I prefer to slightly under pitch rather than over pitch."

I think that a ±20% variation is perfectly acceptable in brewing. If you're going by weight or volume rather than counting, you won't be able to do much better than that anyway. Stick to the MrMalty numbers and you should be roughly where you need to be.

I would prefer slight over-pitching to under-pitching, FWIW.
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Offline denny

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Re: Yeast cell count...Starters...Gravity range
« Reply #8 on: March 26, 2012, 10:49:07 AM »
I would prefer slight over-pitching to under-pitching, FWIW.

Same here.
Life begins at 60.....1.060, that is!

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Offline roguejim

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Re: Yeast cell count...Starters...Gravity range
« Reply #9 on: March 26, 2012, 12:15:50 PM »
Denny can answer how he does it, this is my $0.02.

I have been chilling my starters for some time, decanting and pitching the yeast slurry. Now the same is done for ales.

If you make a lager you have a huge starter, and it is a big fraction of the beer that is not like the beer you are brewing.  Heck 2 liters for a 5 gallon batch of ale is 10%.  If you spend time figuring out the OG and IBU, why have that go out of whack with 10% starter (unless you use that in the calculation - I never did).

Jeff, what size starter are you making for your pilseners, assuming a ~5.25gal batch?

Offline hopfenundmalz

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Re: Yeast cell count...Starters...Gravity range
« Reply #10 on: March 26, 2012, 01:36:39 PM »
Denny can answer how he does it, this is my $0.02.

I have been chilling my starters for some time, decanting and pitching the yeast slurry. Now the same is done for ales.

If you make a lager you have a huge starter, and it is a big fraction of the beer that is not like the beer you are brewing.  Heck 2 liters for a 5 gallon batch of ale is 10%.  If you spend time figuring out the OG and IBU, why have that go out of whack with 10% starter (unless you use that in the calculation - I never did).

Jeff, what size starter are you making for your pilseners, assuming a ~5.25gal batch?

I made a 1.048 OG Bo-Pils with 2 different yeast to pitch into about 5.5 gallons each.  Using stepped starters with 3 steps, one was 1.5L the other was 2 liters.  The difference was that the WY-2278 that I found was several months old. Used this calculator, as it is easy for this old guy.
http://www.yeastcalc.com/index.html

For stonger lagers it gets big in a hurry.
You will need bigger using mrmalty and just doing 1 step, but I know you can run multiple steps by just re-running mrmalty.




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Offline roguejim

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Re: Yeast cell count...Starters...Gravity range
« Reply #11 on: March 26, 2012, 02:58:38 PM »
Denny can answer how he does it, this is my $0.02.

I have been chilling my starters for some time, decanting and pitching the yeast slurry. Now the same is done for ales.

If you make a lager you have a huge starter, and it is a big fraction of the beer that is not like the beer you are brewing.  Heck 2 liters for a 5 gallon batch of ale is 10%.  If you spend time figuring out the OG and IBU, why have that go out of whack with 10% starter (unless you use that in the calculation - I never did).

Jeff, what size starter are you making for your pilseners, assuming a ~5.25gal batch?

I made a 1.048 OG Bo-Pils with 2 different yeast to pitch into about 5.5 gallons each.  Using stepped starters with 3 steps, one was 1.5L the other was 2 liters.  The difference was that the WY-2278 that I found was several months old. Used this calculator, as it is easy for this old guy.
http://www.yeastcalc.com/index.html

For stonger lagers it gets big in a hurry.
You will need bigger using mrmalty and just doing 1 step, but I know you can run multiple steps by just re-running mrmalty.

Thanks for weighing in, everyone.

Jeff, I used the calculator you linked to.  I plugged in a 1.048 lager; 5.5gal batch; 1 month old yeast...

It indicates that a 3 liter starter, in one step, would put me ~50 million yeast cells short of the optimum amount.  The 1 month old yeast w/76% viability is the killer here, and most of the Wyeast available where I live, are usually about a month old on the shelf.  Anyway, how close do you get to the optimum yeast cell amount?  I'm concerned with pilseners here, primarily.  (I suspect that a 3 liter/one step starter would be too stressful on the yeast?)

I went back to the calculator and did a 2 step, 1 liter then 2 liter.  It put me well over the optimum yeast cell amount by about 80 billion.  Any problems with over pitching by this amount in a pils?

« Last Edit: March 26, 2012, 03:11:44 PM by roguejim »

Offline a10t2

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Re: Yeast cell count...Starters...Gravity range
« Reply #12 on: March 26, 2012, 03:26:34 PM »
(I suspect that a 3 liter/one step starter would be too stressful on the yeast?)

Not as far as I know.

It put me well over the optimum yeast cell amount by about 80 billion.  Any problems with over pitching by this amount in a pils?

Nope.
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Offline hopfenundmalz

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Re: Yeast cell count...Starters...Gravity range
« Reply #13 on: March 26, 2012, 04:55:40 PM »
I agree with Sean, no problem.
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