Life expectancy of yeast in cold storage

[kramling]

We have a new brewery and are using liquid yeast. At this point I don't have multiple batches running per week to pitch yeast from FV to FV without having to put some in our walk-in.

What kind of life expectancy should I get with yeast I have pulled off the cone into a cornelius keg and put in a 38 degree walk-in?

The yeast has gone through a single fermentation cycle and has been idle in storage for a week and a half by this weekend. I would like to use it this weekend but want to make sure I haven't lost too many cells.

I don't have a microscope setup properly yet to count cells.

Cheers,
Steve

[beauxman]

Contact your yeast lab supplier. I think storage time varies by strain.
-Beaux

[canyon]

As a general rule two weeks is my rule of thumb. However, I will use properly cold stored yeast slurry up to four weeks(but no more) if need be. I am familiar with a few strains that I wouldn't use past two weeks so it is strain dependent and, as recommended above, talk to your supplier.:)

[Moonlight]

Depends on the yeast. I have gone 8 weeks before, but it may be different for you. More important is how you treat the yeast at wake up time. Plenty of oxygen, correct zinc. Reasonable gravity wort. Rousing may be necessary. Assume extended settling time.

[owen williams]

No more than two weeks...trust me...yeast stains don't come out of your clothes! Just brew more and drink more! --owen
www.successfulbreweryconsulting.com

[billvelek]

Owen, you need to fix your link; "successful" is misspelled and leads to an "OpenDNS Guide" page.

Cheers.

Bill Velek

[brewbong]

A little trick I use is to do a glycogen test, most brewers have ( seldom used and hidden behind the high range hydrometer) a small bottle of tincture of iodine. If you schmeer a bit of your yeast across a white china dish and drop a few drops on it, yeast that contains lots of glycogen (cellular energy) will stain blackish. This usually tells you it is OK to use. I would schmeer a bit of the good stuff first to see how long the reaction takes, sort of a self made tutorial, and then try the questionable stuff.

[owen williams]

Owen, you need to fix your link; "successful" is misspelled and leads to an "OpenDNS Guide" page.

Cheers.

Bill Velek

Right on thanks...owen

[owen williams]

Bill...thanks...

www.successfulbreweryconsulting.com

[lallemand]

You may not have access to a pH meter as yet but the pH of the yeast slurry is a good indicator of autolysis. You would expect the pH of your slurry to be that of the beer at the end of the fermentation so no more than 4.4. Anything higher indicates that the yeast has started to die and decompose :mad: .
Good luck with it!