I have a bucket out in the garage from a batch I kegged 7 days ago. It got pretty cold during that time, very likely frozen, then thawed a bit. Is the yeast still viable after being frozen and thawed? I would assume so, I think I read about people freezing samples but I would like to be sure before I bother to wash and try to use it in the next batch.
7 days in a bucket with a freeze-thaw is not ideal. If you are going to reuse it you want it to be healthy. You could probably throw another beer in there and the yeast that are still alive would do their job. Although, why put 5 gallons of good wort through a sub-optimal fermentation? If it were me, I would collect a scoop and make a starter, then pitch that for the next batch.
I should have been more clear, I wasn't planning on pitching onto the cake, Iwas going to harvest and make another starter, but for the price, I'll just let it go and buy a couple more packs and do it right next time. Thanks!