Harvested yeast - how long will it last

[Leon103]

I have a Vermont yeast and a Conan 644 yeast sat in the fridge for over a year. Would you Use?

The Vermont is some of the trub I took from my last neipa whilst the Conan was harvested from a bottle strange Steve sent.

 

[MyQul]

Yup. Id make a small starter and step up t0 get a pitchable amount. Taste/smell the starter wort at every step up. If it tastes/smells fine then pitch the final amount into wort. Thats what Id do anyway

 

[Simonh82]

You will probably be able to build up a viable starter, possibly after a few steps as a lot of the yeast will have died but some will have held on. Start small and step up.

My concern would be what else might be in there after a year of storage. If there is any bacteria or wild yeast, even in small numbers, you would be stepping them up too. Under normal conditions the yeast will quickly outcompete them but that's based on having a normal cell count and that won't be the case with this.

I tried to use yeast stored for 6 months and the starter went sour, even though the beer it came from had been fine.

 

[Leon103]

I will build some up and see how I go

 

[foxbat]

I'll bet it works, please do report back.