I have a question re: yeast quantities from top-cropping. I've top cropped before, but didn't approach it very scientifically. With a current batch I have (brewed w/ WLP023), I'm attempting to top crop for my next brew. I've found that I can fill a pint jar with the meringue-like cake afloat on the brew from each crop, but after I put the jar in the fridge for a while this reduces down to less than 5% of that initial volume. If I crop every 12 hours, I can get about 1-2 ounces of this slurry reduced from yeast foam after 3 crops. So, what's a ball-park estimate of how much yeast I have? For my next brew (a 3.5 gal, 1.090 October beer), would stepping up this slurry in a 1.5L starter suffice? Thanks for your advice and expertise.
that sounds about right. I've never been scientific with my top cropping either, but it works well although have had a few slow take-offs. What you do have to remember is that is basically 100% viable yeast...so you have to think about it like dry yeast that has a few drops of water in it...not like the cake which has trub and other break material in it.
