[brewsumore]

So, for years, I have found some LHBS's that store their dry yeast at room temp, other refrigerated.  My standard operating procedure either way, has been to toss the yeast packets into my fridge when I get home thinking that most companies recommend this for extended, higher percentage viability.

Until this week when I bought some set out at room temp, and asked the owner why he doesn't store it refrigerated.

His answer was that he used to work at a brewery that used dry yeast, and their practice was to store it at room temp with the understanding that temp swings, i.e. putting it into the fridge from warm, actually ruptured cell walls, making the yeast less viable than if they maintained storage of it at room temp, and I believe this was with the understanding of using it within 3 months.

When I buy dried yeast, should I put it in the fridge for anywhere between a few days and a few months, or should I leave it at room temp?

[mainebrewer]

Well, I don't have any scientific evidence either way. I always store my dry yeast in the 'fridge. I use liquid yeast but sometimes I need a backup and that's why I have the dry yeast. I've left the yeast packet in the 'fridge for a year or more and had no issues when I used it.

[dzlater]

From the fermentis website:
"storage
During transport : The product can be transported and stored at room
temperature for periods of time not exceeding 3 months without affecting
its performance.
At final destination: Store in cool (< 10°C/50°F), dry conditions."
http://www.fermentis.com/wp-content/uploads/2012/02/SFA_S04.pdf

[dmtaylor]

Dry yeast is fully dormant and will last for years either way.  It really does not matter at all.  That being said I do refrigerate mine just in case.

[S. cerevisiae]

Dry yeast can even be stored in one's freezer. The cells contain no water; hence, there's nothing to cause them to rupture when stored at temperatures below that at which water freezes.