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Add Stepped Starters to Yeast Tab


Jun 23, 2011
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Hi Brad,
Would it be possible to add stepped starter calculations to the Yeast tab in V2.0, i.e. have 2 or 3 steps, and take the calculated output from one as the input to the next.

  I'm looking at adding this to the display along with slants as many people using cultured/reused/slants do multiple step starters to get to
full volume.

I have been playing around with yeast culturing for a little bit and I think I have reached by goal.  I have yeast stored in 10 ml vials in sterile water.  I use a couple of drops on a slant to start the growth.  In 3-4 days, I have a flourishing garden of yeast.  By my very crude estimates, I get about 500 cells on the slant and end up with about 500 million or so at the end of 4 days.  That works out to about 10 doublings.  I then transfer to 10 ml wort, 100 ml wort, and finally either 1000 or 1600 ml wort.  (I still working out the final numbers.)  At the end, I estimated about 20 ml of yeast, and by my estimates that should be about 160 billion cells.

Attached is my XLS worksheet for stepping up.  I have plotted the data from White and Zainasheff and used XLS curve fit to get an equation.  I know that the pitch rates that are typically used in culture and much lower than there data, but it is the best I had.  The worksheet is not set up for public distribution and I seem to change something every time I play with it but it is a place to start and you can tweet the numbers anyway you want.

Critic is always welcome.

All the best, David


  • Pitching_Rate-Starter_Calculator.xls
    30.5 KB · Views: 204
+1 to multi-step yeast calculator.  yeastcalc is great, but I would like all my calculators housed in on place. Thanks
+1 for this request.

A filed for observed yeast concentration would be nice, some people have a hemocytometer and scope.  With an observed concentration, growth estimates would be far more accurate than estimating the starting concentration.