I know its been asked before, but how long is yeast good for in the fridge

3rd generation Conan, I have about 200ml in a sanitized mason jar with some starter wort on top of it. It was harvested around September 1st (2015).

Mr Malty is throwing out a calculated viability of 10% based on that date, which if that is true, I’d probably get a better inoculation rate by letting my buddy dip his beard into the wort.

I was thinking of making a 1L starter tonight and getting it on the stirplate, just to wake it up, then doing a 2-3L starter to brew a 14G batch this weekend around Thursday.

I prefer this pitch rate/starter calculator for a more realistic calculation of viability. The calculator also offers a starter over build to save fresh yeast from the starter.

I would begin the yeast building process earlier and just refrigerate the yeast when the starter is complete. Just in case something intrudes on your intended schedule.

I don’t buy that. 4 months isn’t that old, I’ve repitced 6 month old slurry with very good results.


I too have had good results with yeast over 6 months… I wonder how it was saved many years ago with out all we do today? In fact, isn’t that what we are using today? Keeping yer handling practices in check I have to believe you could keep going for a year! Sneezles61

Until fairly recently, I wasn’t able to get smack packs that were less than 6 months old on average. I successfully built up starters from year old packs more than once. You need to plan on taking about one day per month old the pack is to properly build up the starter to pitching strength.

That’s easy; simply brew regularly, and always use the same yeast strain. That’s how it was typically done years ago.

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I brewed a Red IPA using 1/2 a WY1728 yeast cake that was about 3 months old.
I did make a starter and it went from 1.073 down to 1.012 with no off flavors.
Also I did not rinse/wash the cake at all. It was murky looking but very viable.