Washing Yeast After three generations of not being washed . ..

[merkinman]

Should I do it, or would it be better to start with a new culture? What would be the risks / detriments to washing and storing this yeast after it has been used for three batching already without being properly washed (slurry stored in the fridge in a sanitized jar after each use)?

 

[JJL]

The only thing I can think of is that after using the same yeast 3 or 4 batches (washed or not) you are recycling the weaker, most flocculant yeast from the culture. Washed or not, I think I would be a little hesitant to use it again. Just my opinion.

 

[ReverseApacheMaster]

You'll be fine to use it for another generation or two. Wyeast and White Labs generally recommend not using yeast for more than five generations, but on the otherhand, some breweries (I believe Orval does this) use yeast for up to sixteen generations before returning back to new yeast.

I'd recommend washing at your next opportunity so you can keep multiple starters, rather than using a generation of yeast only once.

 

[ajf]

Back in the 1980s when you couldn't get good yeast, I often used yeast cultured from a bottle of Worthington White Shield for more than 3 generations without any problems. (It got expensive having to travel from California to England and back just to get a suitable yeast.)
Nowadays, I always stop after 3 generations at most. I'm sure I could get more out of them most of the time, but I have noticed that the yeast does change a bit from one generation to the next, and I've had a few batches with older yeast where the characteristics have changed very noticeably. As I can get up to 20 brews out of one vial of yeast, the cost of yeast becomes pretty insignificant.

-a.

 

[bdleedahl]

The head brewer at the local microbrewery told me that he is currently on the 26th generation of yeast, and I do believe they make great beer www.paddockwood.com

 

[merkinman]

Nicely put.