Oops, I did that #3 thing somehow... Anyway, I step up from slants 3 times on a stir plate, 50ml to 250 ml to 2L. M.Malty's "Proper Yeast Pitching Rates" does state 4.5 billion/ml, but then goes on to say that, according to Fix, in a slurry, only about 25% of the mass is yeast solids. So I'm...