How long will the yeast be viable for repitching...

[ApresSkiBrewer]

So, as I repitch, I have been splitting the yeast from the carboy into two's... Putting one in the fridge with the intention of re-pitching within a week.... but sometimes I am a lazy piece of shit, and that batch of beer doesn't get done. How long is that yeast good for? Its settled into a nice 350ml slurry, with an inch or so of beer on top.... and I actually have two. One is 4 weeks old, and one is 2.5 weeks old. Should I just build a starter with them... or just dump it and get a fresh culture going? Or could I just feed them a bit on brew day or the day before.... to get them going.... Any thoughts appreciated!


oh... huh. look at the show tonight, maybe I'll just call in... if I'm sober enough to speak complete sentences to the brothers White.

[ziggy]

It should be good for a number of months. Just get it out and feed it some a day before you brew to make sure.

[seanhagerty]

and SMELL your starter, if it smells bad, be afraid

[ApresSkiBrewer]

and SMELL your starter, if it smells bad, be afraid

If it does, then I'll go on a murderous killing spree. Killing yeast... of course.

[SacoDeToro]

As long as things are refrigerated with a protective layer of beer on top, repitches can maintain reasonably viability for up to 2 weeks. Any longer than that and you're best off making a starter. Personally, I try to reuse all my repitches within a week and I've never had any issues there.

[Sethela]

As long as things are refrigerated with a protective layer of beer on top, repitches can maintain reasonably viability for up to 2 weeks. Any longer than that and you're best off making a starter. Personally, I try to reuse all my repitches within a week and I've never had any issues there.

I agree. Longer than about a week and the viability starts to drop. Longer than 2 weeks and you've lost ~90% of your viable cells (10^10 cells/ml is now down to 10^9 viable cells/ml) which means a relatively low pitching rate. If you want to use the yeast in your fridge, make a starter with them before pitching.

[ApresSkiBrewer]

As long as things are refrigerated with a protective layer of beer on top, repitches can maintain reasonably viability for up to 2 weeks. Any longer than that and you're best off making a starter. Personally, I try to reuse all my repitches within a week and I've never had any issues there.

I agree. Longer than about a week and the viability starts to drop. Longer than 2 weeks and you've lost ~90% of your viable cells (10^10 cells/ml is now down to 10^9 viable cells/ml) which means a relatively low pitching rate. If you want to use the yeast in your fridge, make a starter with them before pitching.

So as a hypothetical extreme... If a split off of a yeast cake still smells fine after 4 weeks, I could make a starter, pitch it... and then if that rips up, and smells fine as well... I should be good to pitch into a batch right?

The only reason why I don't want to start from scratch, is because this was a unique culture out of a commercial bottle... that was really clean in the first/second beers it fermented... but the yeast I have for it now is probably coming up on 4 weeks old... out of the carboy. Hm.

[heliboy]

I've been doing something alittle different with very good results. I started with a White Labs Belgian strain and made a barley wine last year. I used the yeast off the secondary and made 4 more beers. What I did was sanitize the plastic vile that the original yeast came in and a funnel and poured the yeast into the vile. I've used this 4th generation to make my latest beer that was an Imperial IPA and it taste great. Once of the viles sat for about 4 months in the fridge before I reused. I'm going to keep reusing and pitching until I notice some off flavors. Next time I will make a starter as I've done this on a few of the repitchings of this yeast. I've heard that yeast can last up to a year before it dies. I say try to grow more with the starter and smell it before you pitch it. If it smells funky, only use it if you intend to make a sour beer. I've always used the yeast of the secondary only as most of my hops go into the primary as hop resins help keep bacteria at bay and I don't want old hops in my yeast culture. Take good notes so you know how to repeat good results and not repeat bad ones.