Stretch out that Yeast Print
Learn - Tips & Tricks
Written by Mark Emiley   
Tuesday, 15 July 2008 19:31
One of the costs with a batch of beer is liquid yeast.  At $5 a pop, that composes roughly 25% of your costs for a batch.  There are very few good reasons not to recycle your yeast from batch to batch.  If you ferment in a primary container then rack into a secondary container, the yeast that settles in your secondary is probably in great shape to start your next batch of beer with a healthy volume and should be relatively free of other strange sediments.  There are a few good ways of propagating your cultures.  You can make bottling day the same day as brewing day and pitch that yeast straight into your new batch or save it for later.  When you are siphoning off for bottling your beer, make sure you leave a little beer (1/4 inch) on top of your yeast cake.  While bottling, make sure to keep a plug or airlock on the mostly empty carboy.  When you are ready to transfer or bottle your yeast, pick up your carboy and start swirling it around to break up the cake and mix it in with the beer.  Once it is good and mixed, you can pour it into your new beer or into a 1/2 gallon growler to save for later (put an airlock on it and put it in a fridge to keep it fresh).  Try to keep the process as sterile as possible, but keep this in mind: with this volume of yeast, I can guarantee you that your fermentations will take off quickly with that yeast as the dominant culture.  You can repeat this process many times as long as you don't start noticing off-flavors.  After a while, mutations may lead to sluggish performance and off-flavor development.  Commercial breweries will perform this up for 15-20 times sometimes before they completely start a new culture.  I think I've gone about 8 times with one culture.  Conducted with attention to sanitation, this process saves a lot of money on great yeast and also ensures you have a healthy starter culture ready to go.