Originally Posted by Odin_Brews
While Im sure you can skip decanting I think optimal for yeast production would be to decant between steps.
I was just reading something about how optimal yeast reproduction occurs at 1.036, post 16 on this thread http://www.homebrewtalk.com/f163/wor...48/index2.html
So if you don't decant let's say your starter ferments each step to 1.010, then you mix that 250 with 500 ml at 1.040 and you get about 1.030 for your second step. That again ferments out to 750 ml @ 1.010 which you mix with 1 liter getting an SG on your third step of around 1.025.
See what I mean? So you would definetly reproduce cells but not likely in the same way that you would or as optimally as you would by decanting each time.
Good point. This approach does seem optimal. The only downside I see is the level of planning this would take. If you're going to cool/get the yeast out of suspension, decant, then add fresh starter wort at every step, you'll need to start your starter earlier than usual. Probably about a week, or more, before your brew day. I don't usually need a multi-step starter, but I'm going to try this approach the next time I do.