North Texas Homebrewers Association

I am aware of two calculations for yeast starters. There is the Chris White/Jamil Zainasheff model and the Kai Troester models (https://braukaiser.com).

• The White/Zainasheff model is based on a diminishing return where adding more starter wort ultimately gives you no more yeast growth.
• The Braukaiser model produces more yeast with the more wort available in a linear fashion. (Blog post: http://braukaiser.com/blog/blog/2012/11 ... st-growth/)

I'll admit I have not read the White/Zainasheff Yeast Book (but I do have it).

I'll will not get into the details of each model, I'll leave that for you to research. I did read about both and I agreed with Kai's conclusions.

Empirically I would run my own test with yeast starters and count yeast cells. Maybe that could be a club project.

Beersmith only has the White/Zainasheff calculator. I use these two online calculators that both have the W/Z and Braukaiser models:

• http://yeastcalculator.com/
• https://www.brewersfriend.com/yeast-pit ... alculator/

What are your thoughts on yeast starters? Which model do you use?

Let me add that there was a White/Zainasheff calculator at mrmalty.com but it does not work anymore.

There is a github project for the http://yeastcalculator.com/ site at this location https://github.com/dboyd13/YeastCalculator

I also found this calculator on Morebeer's site. It has more options related to stirplates:

https://www.morebeer.com/content/yeast_pitch_calculator

I've been using Brewersfriend for everything (recipes, water calcs, yeast calcs). Their yeast calculator uses the Braukaiser model for the first step, and the Chris White model for the subsequent steps. In their discussion about the calculations, they note Braukaiser should only be used with stir plates.

https://www.brewersfriend.com/yeast-pit ... calculator

Terry,

Brewers Friend allows you to select the model you want on each step independently.

The Morebeer calculator allows you to select no aeration or Stirplate for Troester and None, Shaking and Stirplate for White.