Maintaining Yeast Strains Long Term
 

I want to start washing yeast. I been reading about it for a couple of days, and many people seem to say that you can re-use yeast for around 10-15 generations. I'm curious how professional breweries maintain their strains of yeast, since I'm sure most of them have gone through many more generations than this. Are they operating with such a huge amount of yeast in storage, that the generation issue never crops up? Or do they take advantage of equipment / technology unavailable to the homebrewer?

The larger breweries would be using slants, and would propagate their yeast from those. Smaller ones may periodically purchase new batches of yeast. When I was brewing at a brewpub, I used several different strains, depending on the beer, so I was always buying yeast. I'd buy them at my LHBS, brew a 5 gallon batch, which, when pitched at high kraeusen, would produce a vigorous fermentation for a 15 bbl batch.

I think a lot of breweries will save older generations of yeast and propagate from that older generation after they get too many generations in and the yeast begin to change/mutate. Once they start to drift away from the original yeast characteristics, they go back to that original yeast culture, take a small amount, propagate that to a larger amount, and start over with their 1st generation (or 2nd or 3rd or whatever it is) instead of harvesting from later generations.

yeast-harvesting-novel-approach


Cheers!

I have a question about the link posted above. I came across this info for harvesting yeast from starters the other week and cant wait to give it a try. My one question being, is the last step really necessary? Why would the yeast need to be transferred from a jar filled with starter wort and yeast to a jar with just water? Does that really effect the shelf-life of the yeast, and if so, by how much? Would love to omit the last step if possible but dont mind doing it if need be. I cant wait to start my own yeast bank!

For longer term storage (2+ weeks), it is best to keep your yeast in deoxygenated water rather than fermented beer.

Thanks for posting this, very useful! I have been doing the yeast washing thing for a while now and it has been working but is a pain in the butt. And having lots of very clean yeast with this way is way better any ways!

Thanks again!

My pleasure!