Heh a little bit of thread resurrection
I pitched 11 g of Notty Lot 108117102 with expiration date of 5/2011 and got no activity in 48 hr. I mean NOTHING. No apparent multiplying Yeast in solution. Wort was crystal clear, and, of course no airlock activity. Interestingly, I had two other packets of this 'same' lot, but like other posts here, the others had exp dates of 6/2011. The last time I used it, it was already a month past expiry and still took off like a rocket. This time, nothing. Can't complain since it is almost 6 months expired now. After 48h I pitched a new packet of Notty, 1080363V exp 7/13 and it started forming yeast islands in about 4 hours, and started krausen in about 10 hrs... THAT is more like the Notty I have known and loved every other time.
I suppose it is remotely possible that the first packet finally kicked in..but I kind of doubt it. Neither one really foamed during rehydration and the second pack was pitched from a relatively warm rehydration (~75 deg F) into cold wort (~64 deg F) while the first was pitched at about the same temp (~80 deg F for both). In the past I generally pitched more along the lines of the 80 degree wort and yeast and never had a problem.