Unrefrigerated Wyeast smack pack

[Bizoune]

Hi! First post ever after reading many threads. I've ordered 4 smack packs that were to be delivered on Friday. But they are now stuck at a USPS warehouse and I won't be able to get them before Monday afternoon. I'm worried that I won't be able to use them because of the hot weather on the weekend (upper '80s). They were packed with ice packs but I'm sure everything is thawed by now. I'm planning on putting them in the fridge as soon as I get them.

Should I be worried that the hot weather will spoil the yeast?

 

[Malticulous]

80s is nothing man. My WLP300 was 100F when I got it a few days ago with a thawed ice pack. It took over 24 hours to get my 1 gallon starter going.

 

[ThreeDogsNE]

I got some recently after a similar weekend hold in the 90s. I smacked the pack not too long after I got it, and left it out. It took a few days to swell, but the yeast did fine...eventually. If you plan to use the pack without a starter I would allow a few days. If you are making a starter with a stir plate, then you might want to go ahead and pitch it into the starter with more than the usual lead time.

The heat may have killed some yeast, but is very unlikely to kill them all unless it is boiled. As far as the yeast are concerned their dead comrades are pretty much just a nutrient source that smells bad to us. Once they are given decent growing condition they will start growing and dividing, and the powers of two start to give you huge numbers of cells. If you start with a lower number of cells you just need to allow more doubling time for a few more generations of yeast to get to your desired starter.