Year Old Yeast

I'm considering using yeast (wyeast 1056) that's a year old. I've washed it thoroughly with sanitized water in a sanitized vessel before storing it in a sanitized air tight jar, which has been kept in the refrigerator for over a year (approx. 13-14 months.)

Anyone ever attempt something like this? What is the worst that can reasonably happen: perhaps yeasts that don't ferment, in which case I can simply go out and buy a new 1056 smack pack?

Do at least a two step starter with it. Yeastcalc can help you to figure out the size for the batch you'll be brewing.

+15 to golddiggie

Decant any liquid, starter and go.

I've used save yeast that has been a lot older than a year before.