So I wandered headfirst into a rabbit hole today with the help of Google Search. The quest was for a simple answer as to methods for estimating yeast cell counts in a slurry derived from an over-built starter. That number is almost always the entering argument for any of the many yeast pitch...
Does anyone know of a resource similar to this yeast comparison chart, but for dry yeast? That is, what are the equivalent strains of White Labs and Wyeast...
Two things you'll have to watch out for when using slurry estimates is the percentage of non-yeast material in your slurry and the viability of your yeast. While your estimated concentration of yeast looks good, what protocol did you use to arrive at it? Again your starter process looks fine, but just remember that without doing a visual viable cell count it's just an estimate.
Assuming the 16 oz jar is the slurry and the bottom 8 oz layer (50%) is yeast solids, using the Wyeast formula below, I get an estimate of 284 billion yeast cells. 8oz = 237ml 237ml yeast solids x 1.2 billion = 284 billion cells (at harvest date) Using Homebrew Dad's Yeast Starter Calculator...
Try boiling a packet of bakers yeast and adding that. Yeast will feed off of dead yeast cells, which conveniently contain just about everything yeast need to grow and reproduce.
I've read all of these threads about how much yeast you need to pitch. One of the links actually said you would need a 2.5 gallon starter for 5 gallons of beer (the point was that most people don't pitch enough yeast). Obviously, people get reasonable results with a single pkg of dry yeast or...