Author Topic: Pitching Yeast by Weight...  (Read 1577 times)

Offline mmitchem

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Pitching Yeast by Weight...
« on: August 15, 2012, 04:35:22 AM »
Greetings All!

I have read from a few sources (Kai's blog most recently) that pitching yeast by weight is the way to go. I can definitely see where this would be advantageous, especially as my batch sizes increase. Is there a quick and dirty way to estimate yeast cell count based on weight? Thick slurry vs thin slurry? Thanks for the help in advance!
Michael P Mitchem
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AHA Member since 2011

Offline AmandaK

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Re: Pitching Yeast by Weight...
« Reply #1 on: August 15, 2012, 05:57:10 AM »
I would use Mr. Malty's pitching rate calculator. http://www.mrmalty.com/calc/calc.html

The third tab has a slurry calculator.
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Offline Kaiser

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Re: Pitching Yeast by Weight...
« Reply #2 on: August 15, 2012, 05:58:05 AM »
Jamil has some numbers in his Pitching Rate Calculator. I have some numbers too and plan to publish them as a follow-up to the blog post.

For a well flocculating lager yeast I get about 4-5 Billion cells per gram in freshly propagated yeast and 2-3 B/g in yeast harvested form a primary.

The numbers seem to be a bit different for Ale yeasts. I have to check the few data points I have at home.

Kai

Offline mmitchem

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Re: Pitching Yeast by Weight...
« Reply #3 on: August 15, 2012, 06:26:12 AM »
I have used Mr Malty for most of my starter calculations over the last few years and also have noticed the slurry tab as well. It has always done me right :)

Kai - I mostly do lagers as well and saw the billions per gram calculation in your blog post. I must admit that I do a lot more lagers than ales at this point so that information is top notch. With that in mind to pitch around 500 billion cells I am looking at a thick slurry of around 111-112 grams. Does that sound about right?

Also, what are the differences in weight with ale yeast? More cells? Less cells? If I were going along with the 4.5 billion per gram assumption it would put me at pitching 55-56g for 250 billion cells. Is that a safe assumption?   
Michael P Mitchem
Beer and Ale Research Foundation (B.A.R.F.)
AHA Member since 2011