So, I've got this saved 3rd generation White Labs California Ale Yeast in my fridge. This is just saved trub that I put into sterilized mason jars. I was planning on using it this weekend. I'm worried that its been in there too long, I guess the only way to find out is to make a starter and check it out.
You should be fine and have enough time to get new yeast in case it is dead. Make a starter and pitch it with a little of the saved yeasy to grow lots of new yeast from it. If it smells foul or doesn't get starterd, throw it out and get a fresh yeast culture
just thought I'd update on this. It worked just fine, although the starter took a while to get going. I actually made a really big starter (1/2 gallon) and used it on two batches. So that one vial of white labs yeast made five 5 gallon batches. Not too shabby if you ask me!
I just used some yeast I had stored that was about 6 months old and it was OK. Like everyone said, just make a starter, if it goes and smells and tastes good, its good! I used it for an irish red and then pitched a barleywine on that yeast cake.