Yeast Starter Calculations: Zainesheff Vs. Troester

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Satisfaction

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I've been making yeast starters and using http://yeastcalc.com/ for a while now, always trusting the Jamil and Chris White calculations. Recently Kai posted a write up on his blog http://braukaiser.com/blog/blog/2012/11/03/estimating-yeast-growth/ talking about the original calculations were possibly derived and how his cell counts showed the growth curve being different.

Not owning a hemacytometer, I follow the suggestions of these calculators on where the pitch rate should be.

Has anyone verified the methods?

Is Jamil a recipe for over pitching or Kai going to lead to under?

Interesting to hear everyone's comments.
 
I'm having the same "trouble" as well... I want to believe Kia's write up because I hate making multi-step starters and buying DME! With his calculations you can almost get a good pitch rate for any 5 gallon batch of beer with a stir plate and a 2L starter. I'm interested in what others have to say as well. His write up makes sense..
 
Last weekend I put together a Schwarzbier, a lager of modest size. The difference that really struck me was the Jamil stir plat method would of had me making approximately 4 Liters of starter and Kai was only 2.5L

To me this is a huge difference in starter size and surprised me.

Funny enough I split the difference. :)
 
I sat in on Kai's presentation at this year's NHC and, while he has a lot of good research behind his numbers, he admitted that he's made his experimental observations using only one strain of yeast. While he's made a lot of very good and very valid measurements thus far, I think its a long way still until he approaches the amount of experimental data that Jamil had to draw on for his calculations.

Basically, Jamil's numbers seem to represent a good generalization across all strains and all pitching rates, while Kai's seem far more specific for various pitching rates and for a specific strain - wish I could remember which one off the top of my head, but his website should list it.
 
Satisfaction said:
Funny enough I split the difference. :)

Lol this is what I usually do.

Although, with all the awards Jamil has collected its hard to believe that he's doing something wrong. But then again, he has always preached that its way harder to mess up your beer by over pitching, so he could be over pitching and just not experiencing any negative effects other than the trouble of creating larger starters.
 
My thought is someone should brew up a 10 gallon batch and split it, pitch one at the Zainisheff rate and the other at Troester. See what you get. I'm not volunteering though! Plus, if one batch did turn out better it still wouldn't prove true for every strain and every style. Ahh yet another unsolvable debate!!
 
It was an ale strain -1007 does seem to ring a bell, but don't take that for gospel without checking his site.
 
I'll be honest. I haven't actually used a calculator for a starter size in some time for my beers. BUT.... this is ever since I have moved to slants and grow a 3 step starter for each beer:

  • first step off slant is 20 ml or so
  • second one is about 150 - 200 approx
  • third is in my 2 lt flask at about 1.7 liters

Each step is (roughly) an order of magnitude so the freshness of my yeast is tops, I usually start this process 3-4 days prior to brewing and I do this for all Ales under 1.070 or so, and have noticed great results, clean fermentations appropriate for each given strain used.

I am sure there is a wider range of "forgiveness" for pitching rates, and I am positive it does have an impact on the overall flavor of the beer, but if you have tight temperature ranges and good oxygenation procedures I am willing to guess that the differences in flavor between Jamil and Kai's methods would be subtle and hard for most brewers to discern
 
WY2042 he says. lager strain.

Very practical experiment. I very much appreciate his recognition of how an agitated vs. non-agitated culture behave differently and how that has to be accounted for specially. His normalization of the data based on a growth per extract ratio makes a lot of sense also.
 
I was following some of the stuff on the Woodland Brewing blog that dealt with lots of yeast growth and handling issues. He was doing scope counts and everything. I was impressed with his approach and the level of data he was presenting. I'm sad to see little/no activity there in quite some time, but the data from his yeast starter experiments is awesome and related to this topic. I high recommend checking it out!

http://woodlandbrew.blogspot.com
 
Kai's experiments are nothing if not rigorous and systematic. I wish he would hang out here more often again.

Kai also published his test methods, and his raw data. I have never seen anything but a summary and synopsis of the White/Jamil data. That doesn't make it less valid, but the element of faith shouldn't be necessary for the sake of science.
 
I was under the impression that Jamil's numbers were extrapolated from experiments looking at relatively high pitch-rates into each stage of the starter, while Kai covered a broader range of conditions? (I think that's on the yeastcal page somewhere, anyways). Regardless, I've done a handful of cell counts of my finished starters and found the yeast numbers to be closer to Kai's numbers.

Bryan
 
I have used Kai's numbers since they were incorporated into YeastCalc and have always had my beer's kick off within 12 hours ith no detectable off-flavours. My wife, whose taste buds are far superior to mine would have noticed something off.
 
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