4 weeks shouldn't be a problem, I've done it before. Can't tell you where the "line" is, but at 4 weeks you should be safe. Especially if you make a starter with the washed yeast, like you should anyway.
Originally Posted by petey_c
"Lets say your local bar pours an American pint where 15% of the beer is missing due to headspace. Every 6.66 beers you drink you 'll have been missing 1 entire beer". 6.66 beers!. I wonder who's really responsible for the missing beers... I don't know, maybe Satan??!