Dry Yeast Left @ Ambient temps for 3-1/2 weeks, Are they dead?

During a recent move, my dry yeast container was misplaced and as a result ended up being left out @ ambient temps for about 3-1/2 weeks (normally I keep them in my beer fridge). Any thoughts on whether or not this will affect their viability? It is mostly US-05 and windsor.

Cheers,

Greg

I usually don't suggest starters for dry yeast, but you might want one for this. If they aren't dead, they're extremely sick.

From Danstar site...

"Active Dry Yeast, at <5% moisture, is originally packaged in an oxygen free atmosphere either via nitrogen flush or vacuum. Under these conditions they will loose about 20% activity / year when stored at 20C.(68F) and about 5% activity / year when stored at 4C.(40F)."

Should be fine if it's not too old.

LHBS sells dry yeast off the shelf, liquid yeast from a fridge. I've never had any trouble with either. I wouldn't worry about it unless they're real old or got real hot.

Having said that, moving trucks can get REAL hot. I've seen plastics melt during moves in summer. If by ambient temps you mean moved in a truck, it may be worth doing a starter with one to test, and if it goes OK, I'd just pitch the rest as if nothing happened. If the starter fails, I'd just toss them all. If you just mean they got left out after the move, then don't sweat it.

Memorex88 said:

From Danstar site...

"Active Dry Yeast, at <5% moisture, is originally packaged in an oxygen free atmosphere either via nitrogen flush or vacuum. Under these conditions they will loose about 20% activity / year when stored at 20C.(68F) and about 5% activity / year when stored at 4C.(40F)."

Should be fine if it's not too old.

Click to expand...

OK, so 3 1/2 weeks over 52 is less than 2% loss...I would not be concerned.