Can Dry yeast go bad

[Warwick316]

I just got back into brewing and I have a pack of S-05 that says expires 2007. It has been refrigerated the whole time. Can I still use this or is it bad?

 

[aidan]

Yes it can go bad so most likely it's not a good idea to use it given it is over 3 yrs out of date.

 

[weirdboy]

I dunno yeast is pretty hardy stuff. I would get an extra packet as a backup, and try rehydrating it on brew day. If it looks active when you rehydrate it, just try pitching it and see. You may get a bigger lag on an old packet, which maybe you don't want if you are going for a clean fermentation profile.

Although, if it has been stored at room temps and/or high temps then it's probably not too good at this point.

 

[dcp27]

S-05 is pretty cheap so I'd just buy another pack to play it safe, but if you make a starter with the old pack you should be good.

 

[rodneypierce]

I had a pack from 08 that had been stored in the basement in about 65* temps. I just pitched it here a few weeks back, and about 10 minutes later I could smell the "bread" smell, which told me the yeast was alive and well. The beer fermented just fine.

 

[Warwick316]

I think I'll make a starter and see if it ferments any. Thanks