Question about Stored starter?

[KoedBrew]

Hey everyone, I made up a starter about 3 weeks ago for an oatmeal stout...Brew day came and we brewed only brewed a Saison instead of Saison and Stout.
So on Brew day I stuck the Starter (still in flask with foam top) in the fridge, basement beer fridge not much action lately.

Now 3 weeks later Sunday we are brewing the Stout. Would you use the yeast or should I be worried about evil infectors?
Thanks

 

[stpug]

If you're confident on your sanitization of the equipment used to create the starter, and the starter still smells decent, then I'd use it. Granted, most starters are NOT going to smell great because you're outside of good fermentation ranges, but it should still smell reasonable. I even taste the decant liquid for anything too "off" (thinking bandaid, pure sour, too tangy, grossness, etc) and judge from there. I was given a washed yeast from a friend and when I finally got around to using it (1-2 months later) it smelled very off and tasted terrible (bandaid and gross) - needless to say, it went down the drain.

 

[LovesIPA]

I would be more worried about the viability of the yeast than I would infection. At three weeks you're rolling the dice on how healthy the yeast are.

 

[stpug]

I would be more worried about the viability of the yeast than I would infection. At three weeks you're rolling the dice on how healthy the yeast are.

I don't agree, completely. While I don't doubt some loss of yeast in 3 weeks in the refrigerator, I highly doubt it amounts to very much (5-7% maybe is my guess). Yeastcalc estimates about 15% viability loss for 3 weeks. I suspect that's a "padded" estimate to cover the variability between yeast strains. But if you take their estimate then 15% loss is about what you're looking at.

IMO, there is A LOT of flexibility in yeast pitching to still produce good/great beer. People all the time underpitch by 50% or more and love the stuff they produce; while others overpitch by 10x on yeastcakes and love the stuff they produce.