Edit: Apologies, this thread should have been in the iPhone Application section. Can a mod move it for me? The calculator on the website has the same results, so it is not iPhone specific. Reading through John Palmer's "How to Brew" (3rd Edition), Chapter 6 "Yeast", table (9) for "Estimated Final Yeast Count (Billions) Based on Initial Count and Starter Size". When comparing between the iPhone App and John Palmer's Table 9, there's major differences in the Final Yeast Cell Count. For Example: Using the iPhone App (Starter page): Starting Yeast Count: 100 Billion cells Starter Size: 1 Liter Gravity: 1.040 Ending Cell Count: Braukaiser - Stir Plate: 260 Billion Cells White - No Agitation: 151 Billion Cells White - Shaking: 201 Billion Cells White - Stir Plate: 251 Billion Cells Per Table 9 of How to Brew, 100 Billion Cell Count with 1 Liter starer: 172 Billion Cells. Table 9 doesn't state which "Growth Model and Aeration" they used. Am I reading something wrong here? As a side note, I think the "Making a Starter" in the same chapter is incorrect. "Boil a pint of water and add 1/2 cup... [DME]". I think that yields a ~1.080. I'd have to check my notes at home, but I believe it should be a quart, not a pint.