I have some WhiteLabs California Common yeast that I found buried in my fridge. It was expired in 2011. About four or five days ago I made a starter with 1/2 cup DME and a pint of water. It's in a warm dark spot and didn't do anything noticeable for the first three days or so. Then just since yesterday and last night I am noticing the airlock bubbling a lot but no krausen has formed that I can tell. My question is about what to expect. Will the profile of the yeast still be the same if I can feed it back to life and grow its numbers enough to ferment a batch of beer or will I get adverse effects from using such an old specimen?