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Add Stepped Starters to Yeast Tab

MPBCBrooer

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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.

Thanks
 
Thanks,
  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.

Brad
 
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
 

Attachments

  • 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.

thx
 
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