Here’s a relatively quick question for those of you brewers more seasoned than I. I’m currently in the process of reusing my Cream Ale yeast. After bottling my fermented beer, I poured off the top layer of wort, poured that second, creamy, beer aroma-y yeast sediment into a plastic container and dumped the trub. I refrigerated the yeast and that was about two weeks ago. My question(s) are as follows: Is there an expiration date on that refrigerated yeast and if not, once I boil/ sanitize some water and wash the yeast, how much should I reserve to make another 5 gal batch of beer? Is it possible to make enough yeast to make 2 batches? Once the second batch is made, can I re-use that yeast as well? Thanks for any responses and stopping to read.
The above is an alternate view on yeast washing and dumping trub.
To answer your question, there is no expiration date on yeast. There a portion of the yeast that will “die” off over time. That amount is up for debate.http://woodlandbrew.blogspot.com/2012/1 ... ility.html
I pretty much follow the thoughts in that article. I separate the whole cake into 2 or 3 containers and refrigerate. I try and keep the re-use cycle to a 3 month maximum and have never had any problems.
I found that harvesting yeast from the secondary is even better. You don’t get as much as from the primary, but there is very little other material present. I’ve only done this a few times so far, but it’s worked well. A starter is a must to get the counts up to the proper level.
I have a Pilsner that I just pitched from a lager secondary from 2 months ago, and the starter worked great, but I had worries after I pitched it. After about 24 hrs there was no obvious activity, so I lifted it out of the cooler and gave it a swirl and the airlock spewed forth sanitizer foam. Apparently all the CO2 was in solution due to the cold temp, and swirling it released a bunch. Guess it’s OK after all! The original lagers I did (3) were primaried in the coldest part of the winter in the basement, but at the higher end of the temp range, around 58F. I have the cooler set to the lower end, 50F, so maybe the greater activity I saw before was due to less dissolved CO2 at the higher temp.
I also read a great post, probably on HBT, but don’t have a link. This was about saving a sample of the starter just before you pitch. This gives you an almost totally clean sample to start with, and you can repeat this multiple times. I’m going to do this a few times with different strains and build up a collection of them. Also requires a much smaller container. I just by chance had 4 liqueur mini bottle (1 oz?) given to me the day I was brewing with a starter, and they are perfect. 30 - 50 ml lab bottle work great too, I read. Another post I read takes it one step further and freezes the samples.
I even did a small Hefe batch with yeast saved from a bottle to compare it to the rest of the batch. My daughter really likes the Hefe’s, and she had a Bells Winter White (IIRC) that she loved, and had to try their yeast in our Elderberry Hefeweizen. It’s going to bottles tonight, so no results yet.
Your process is fine but you may be leaving some good yeast behind. After I rack my beer off the yeast, I pour in about 3/4 gallon of cool water, swirl everything up and lay my carboy on its side for about 15 minutes. I pour all the liquid into a gallon jug or 3 jars. To your questions:
I’ve reused yeast over a year old. Feed it well and you can bring 1 yeast cell back to billions…
Don’t wash the yeast again. I think you’re fine with what you have. I usually use about 1/3 of the yeast for a single batch. This means 3 batches for each cake. I will reuse yeast up to 5 generations. As the number of batches grows exponentially, theoretically, by the 5th generation, you can get 121 batches out of one package of yeast. Practically, that’s difficult because by the 5th gen you’d have to be fermenting 81 batches simultaneously.
I’ve found that the 1/4" of beer left in the fermenter is enough to loosen everything up. No need to add any water IMO.
I like to be able to really shake things up and have a large enough medium for the trub and yeast to separate…yeah, I know, woodland brew…
By adding 3/4 gallon of water, I know when to stop filling up my gallon jug or can better split 3 jars equally. I also like to keep a lot of space between the liquid surface and the harvested cake.