Is my yeast still ok to use?

[Superstorm]

Hey everyone, I have a new unopened packet of safbrew S-33 that I bought about a month ago and I was planning on using it on an upcoming batch. But, I have been storing it in it's original packing envelope in my room and the temperature in my room is in the high 80's to 90's every day and then gets cooler at night. Is it ok to still use this yeast since it's been exposed to high temperatures for this long?


Sent from my iPhone using Home Brew

 

[porterpounder]

I have used a few shops that store their dry yeast at room temp. Never had a problem with viability, even though the yeast abuse makes me cringe.

 

[duboman]

Yeast should be fine but storing in the fridge is ideal moving forward. I would certainly rehydrate the yeast prior to pitching

 

[TopherM]

There was a paleontologist a few years ago that found a 35,000,000 year old yeast colony in the stomach of a bee encased in amber. The guy extracted the yeast, made a starter with it, and used it for a beer, and the yeast were viable, propagated, and fermented the beer.

I think your warm packet from last month is going to be just fine

Just the facts, though, standard brewing yeast LOVE temps in the 80/90s! That's where they'd always be if they had the choice! As a rule of thumb, yeast start getting debilitated around 125F and start actually dying around 140F.