I used to do this all the time - brew a smaller beer with the strain of yeast I wanted to use for a big beer and use the built up yeast on the second, big beer. For whatever reason, I've gotten away from that and have been buying yeast like crazy.
No more. For our next four batches, I'm doing a Helles with Wyeast Bavarian Lager yeast and will use the built up yeast to ferment a big Bock.
I'll be using Wyeast's Ardennes yeast to brew a Trappist Single and then using the built up yeast for a Belgian Golden Strong.
My method has been to rack the small beer off the yeast and trub at the bottom, leaving a little liquid, swirl it around and pour it into a big, sanitzed Ball jar or two. Pop it into the fridge, brew no more than a week or two later, let the yeast warm up to room temp, decant, and pitch into the bigger beer.
Some folks worry about the trub, try to separate it out, etc., but I usually just pitch the whole thing.
No more. For our next four batches, I'm doing a Helles with Wyeast Bavarian Lager yeast and will use the built up yeast to ferment a big Bock.
I'll be using Wyeast's Ardennes yeast to brew a Trappist Single and then using the built up yeast for a Belgian Golden Strong.
My method has been to rack the small beer off the yeast and trub at the bottom, leaving a little liquid, swirl it around and pour it into a big, sanitzed Ball jar or two. Pop it into the fridge, brew no more than a week or two later, let the yeast warm up to room temp, decant, and pitch into the bigger beer.
Some folks worry about the trub, try to separate it out, etc., but I usually just pitch the whole thing.