One of the risks of ordering yeast online where I live is that we can see days with highs in the -10s F.
I received a package of Wyeast 1007 that was nearly frozen solid (my fault). It was still a little slushy, similar in consistency to an orange juice concentrate.
I slowly thawed it out in a fridge, then to room temp. I smacked it and when I checked back 4 hrs later it was swollen. Not tight but nearly full. This seemed promising. (fyi: The customer support rep I spoke with at MoreBeer thought the yeast would be dead. Wyeast's website recommended using the yeast if the pack swelled.)
I then pitched to a 1000 ml starter with stir plate and when I checked about 8 hrs later it looked milky and active. The krausen was overflowing the flask even while stirring.
Everything looks good.
My question:Should I be concerned that the freezing may have damaged this yeast?
Or am I good to go now that I see signs of healthy yeast activity?
I plan to step up one more time before pitching to a 2000 ml starter prior to brewing.
Any suggestions or feedback is appreciated!