Liquid Yeast Shelf (Fridge) Life?

[CiderJoe]

I've been using liquid yeast alittle recently. Not really as great as I would have hoped. Seems to take longer to prepare and all that. The one advantage seems to be I can get alot more types of yeast than you can normally with dry. Anyhow, what's the shelf life on the stuff? I just used a WYeast ####? London ESB over the weekend. The manufactured date on the package was July 2006. It's fermenting away, but I was wondering if it was still in its optimal condition.

Thanks,
Cider

[Otis_The_Drunk]

Only one way to find out if it's viable or not, make a yeast starter and see if anything happens, if it does, I'd pitch it in some wort.

[CiderJoe]

Well, I know it'd viable, but does is mutate or anything if it sits around too long? I dont' think that's a problem with dry yeast as it's dorment. But Liquid yeast is different, no?

[Mad Scientist]

Liquid yeast is sorta dormant, but it is sensitive to age far more than dryu yeast. If it is fermenting, it is likely okay, and will make a nice beer for you. Repitch the yeast cake to save money...

[CiderJoe]

Sounds like a good idea. I'll plan to brew next week or so then. Better to pitch the cake from the secondary, no? Given all the trub in the primary, or is that better?

[HogieWan]

Originally posted by CiderJoe
Sounds like a good idea. I'll plan to brew next week or so then. Better to pitch the cake from the secondary, no? Given all the trub in the primary, or is that better?

The yeast in the primary is a better choice because you are choosing the faster flocculating cells. Also, yeast in secondary have reabsorbed some by-products - lager yeast do this more and it is recommended to NOT use secondary slurries from lagers. However, with keeping the primary slurry, you do have to keep the trub though. This is one of the benefits of a conical. You can dump the trub early and then collect the quick dropping yeast to use in the next batch.

[Mad Scientist]

No, always use the cake from the primary. the yeast in the seconday cake is older, and has been stressed by the lack of tasty maltose to eat.

[CiderJoe]

Thanks guys. Maybe I should think about brewing this weekend then. Only thing is my wife will kill me as I brewed last weekend and used up our whole Sunday to do it (Saturday was ruined do to bottling the previous batch) SO , looks like I won't be doing that. But it I plan ahead for next time...

[BrewDog]

Originally posted by Boerne Brew
No, always use the cake from the primary. the yeast in the seconday cake is older, and has been stressed by the lack of tasty maltose to eat.

Plus, secondary yeast are the ones that didn't floc out. By going generation after generation w/ secondary yeast, you are selecting the low floc cells. This makes it harder and harder for your beer to clear.

[CiderJoe]

I should really read more about Yeast in general. I'm guessing a few of you guys are or can culture your own yeast to save money. I read both Palmer and Charlie Z's stuff on the subject, but just don't have the space to do it.

[Mad Scientist]

I repitch.

[BrewDog]

I repitch when I can or save some out of the primary in a 1/2 gal growler for later use. I've never had a problem doing this, the key is SANITATION.

[generalzonzo]

Originally posted by BrewDog
I repitch when I can or save some out of the primary in a 1/2 gal growler for later use. I've never had a problem doing this, the key is SANITATION.

BrewDog, do you put the yeast in the growler with some of the fermeted beer and fut in refrigerator or you rack off most of the beer, add the primary sediment and then add fresh wort to get it going again then store? Thanks.

[BrewDog]

I rack off the primary into the secondary first. Then, there is usually a little bit of beer left covering the yeast/trub. I swirl that around a little and pour it into the sanitized growler. If its got a lot of trub/hop debris, or I know I'm not going to use it within a week or 2, I will use the yeast washing steps outlined here (http://www.beertools.com/html/tips/008.shtml).
HTH-

[generalzonzo]

Nice, thanks.

[toneyc]

When I was brewing 3 out of every 4 weekends, I would parallel propagate my yeast to save money:

http://hbd.org/brewery/library/yeast-faq.html#part_four


:)
Toney.

[BeachBrewer23]

I've been interested in culturing as well; bookmarking this thread

[barleyburps]

I always swirl my leftover yeast in my primary buckets to froth it up (with a little residual beer), then pour it into a sanitized jar, top off with some tap water, then cover the whole thing with aluminum foil and store in my fridge until I need it again. i've stored and reused lager yeast that was 3-4 months dormant at a time.

[barleyburps]

and I've used strains of yeast for 30 generations with no problems. Obviously it's going to mutate somewhat generation to generation, but it can still give you a very good beer.

[dparsons]

The shelf life is specified at 6 months from the package date. Really, the older the yeast pouch the fewer live cells will be left in the package. It will take them longer to get healthy and build up a population.