I'm about to make a starter of WY2487 HELLA BOCK for a maibock I'm brewing next week. Here's what I know:
wort volume: 6 gallons
OG: 1.070 (17.5 plato)
yeast "born on date": 01/25/11
Mr. Malty Pitch Rate Calculator
says that I need 579 billion cells. Another way to look at it is I need 26.5 million cells per ml of wort. In order to get there I need to put 5 packs of yeast in to an almost 12qt starter (Intermittent shaking). I have only 1 pack of yeast, that, according to Mr. Malty is only 22% viable.
Obviously I plan to step up a starter, but I'm not sure where to start. Well, actually I know exactly where I'm going to start, just don't know what that's going to get me.
I'm going to pitch the 22% viable yeast pack into a 1 gallon starter. How do I figure out how many cells that yeast cake has, and then what size the next starter should be? Wyeast has a pretty nifty pitch rate calculator
, but it doesn't take viability into account, and it presumes that i'll be adding fresh wort to the starters, instead of decanting the beer.
I really wish Mr. Malty had a "reverse calculator" of sorts, that would tell you how many cells you get from pitching 'x' amount of cells into 'y' volume of 'z' gravity wort. Is there a formula for this that I'm just not finding?
One thing that I've tried is setting up the calculator for 1 gallon of 1.040 wort with my yeast. Under these conditions I'll achieve the 28 billion cells needed for an ale with a 1.06qt starter. Is it safe to presume then, that using a 4qt starter will get me somewhere in the neighborhood of 100 billion cells? It just so happens that 100 billion cells is the stated amount of cells in a fresh Wyeast smack pack. Could I then consider my fresh yeast slurry to be the same as 1 new smack pack at 100% viability and pitch that into the appropriate size starter? According to the calculator I'd need to pitch 13.48qt, or just over 3 gallons.
What do you think of my logic, because that's ALL
I can come up with!?!
As usual, TIA!