How old is old yeast?

How old is old yeast?

I found two plastic buckets of yeast cake I saved in my fridge about 10 to 12 years ago. They are from a couple of IPA’s I brewed from extract kits back in '04 and '05.
After watching many videos of yeast washing and reusing, I decided to try my hand at it. Tried my best to sterilize and sanitize every thing and I ended up with two quarts of what I hope will be usable yeast.
What do you think?

10-12 yrs.

Yes, but is it any good?

If it isn’t moldy you might be able to boil it up for yeast nutrient, but that is about all. Even that could be risky though.

Would you consider using anything else that was in the fridge for a decade or more?

For $5, get a fresh pack of US-05

And I say do yer mini batch/starter, then you could taste the the wort after, if it does come back to life. I know yeast is cheap, yet as part of being a home brewer is the money conservation also. I’ve got three very old beers that have yeast floating about and am curious… Post after yer test! Sneezles61

Why are you guys discouraging him? I want to know what happens. Is there ANY viable yeast cells left after 10-12 years? I’d guess no, but if he can build up something in a starter, it would be interesting to know that yeast can survive that long.

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I’m with you Rebuiltcellars. Go for it. No Guts No Glory. Keep us posted.

[quote=“rebuiltcellars, post:8, topic:7684, full:true”]
Why are you guys discouraging him? [/quote]

I don’t think anyone is intentionally trying to discourage. If someone asks “What do you think?”, they’re going to get a variety of opinions.

Personally, I wouldn’t plan a 5-10 gal. brewday around 10 yr old yeast. I might try a small batch though.

Working to build up starters from ancient yeast in the name of science is all well and good. Interesting even; I’d like to see the results. But using it for human consumption is another matter.
Even in the fridge dead cells will decompose. Through multiple starters it may be possible to strip out toxic by-products, but still, this stuff should be considered not only bad, but potentially unsafe. There are reasons why cell banks use liquid nitrogen for long-term storage.

I have to go with the buy new yeast crowd. Unless you were to try making a starter and see what happens just in the name of brewing science the risk of losing an entire batch of beer ingredients and your time isn’t worth it.

For an idea how long homebrewed beer lasts, I found a few unlabeled bottles that were about that age. Popped one open just to see what it was. There was almost not flavor so I could not tell. While not spoiled, they were not enjoyable.

A couple months ago I opened a bottle of the first barley wine I made, back in 2003. When it was young (less than 2 years old), it was basically undrinkable because it was so bitter. After about 3 or 4 years it was really good, and stayed really good till it was at least 10. The 12 year old bottle wasn’t bad, but it was moving past its prime.

How a beer will age depends on the specifics of that beer.

Thanks for all the responses! Means a lot!
My goal is to practice building starters with this stuff. Probably won’t pitch it in a brew, but what if I get propagation and it smells good and tastes good. Can be tempting!

FYI Flag porter is partly fermented with yeast salvaged from an 1825 shipwreck in the English channel.

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