DIY yeast culturing

I was reading on some homebrew-oriented sites that you shouldn't save your yeast from batch to batch for more than about 5-6 batches (generations); otherwise, they say, the yeast will mutate too much and you'll end up with an inconsistent product.

It seems to me then that the implication is that you'll have to buy more yeast every five or six generations. This raises some questions for me:

(1) How are the yeast company guys keeping their yeast from mutating? or are they?

(2) What did brewers do before you could buy yeast online or at a home brew shop in order to achieve consistent products? (2b) what do commercial brewers do now to ensure the consistency of their yeast, and, by extension, their beer?

(3) Is there a way to culture a brew yeast strain separately (rather than saving after each batch) in order to keep it consistent? (3b) is there "home yeast culturing" just like there is "home brewing?"

(4) What are people's experiences with saving and or culturing yeast?

1)They freeze yeast from early generations to maintain stocks. They also can get yeast genetically tested so that if a strain drifts or they run out of frozen stocks they can isolate and re-culture the original desired strain.

2b)I imagine they do the same thing as above. Maintain frozen stocks of yeast they like.

3)Many people on here practice yeast washing. Is that what you are asking? There is also threads on how to freeze your yeast in glycerine and maintain stocks of early generations.

washing the yeast is very easy. If you get 6 jars of yeast to use as starters from the first batch you can get 36 more batches if you just reculture one per generation (which works out to about $.25 a batch or so). If you go real crazy and get 6 jars per batch to re-use it grows exponentially and you'll probably run out of storage space.

buffalobrewer said:

washing the yeast is very easy. If you get 6 jars of yeast to use as starters from the first batch you can get 36 more batches if you just reculture one per generation (which works out to about $.25 a batch or so). If you go real crazy and get 6 jars per batch to re-use it grows exponentially and you'll probably run out of storage space.

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could you explain more what you mean by "reculture one per generation"

thanks.

DavidHawman said:

1)They freeze yeast from early generations to maintain stocks. They also can get yeast genetically tested so that if a strain drifts or they run out of frozen stocks they can isolate and re-culture the original desired strain.

2b)I imagine they do the same thing as above. Maintain frozen stocks of yeast they like.

3)Many people on here practice yeast washing. Is that what you are asking? There is also threads on how to freeze your yeast in glycerine and maintain stocks of early generations.

Click to expand...

Thanks. I looked up those threads and found some great info! I'm still wondering about #2 though. What did folks do before Pasteur?

Did the beer just taste different every time?

Jlatimer said:

could you explain more what you mean by "reculture one per generation"

thanks.

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I believe he means if you kept one slurry from each batch of beer you make, rather than 3-5 jars of slurry you can usually get out of a 5 gallon batch of beer.