Made a 1.082 Imperial IPA today. Thought I had two packets S-04, only had one to pitch. I know it's underpitch. Pitched one packet today, planning on pickup up 2nd packet tomorrow at LHBS. Should I be worried about any ill-effects? Never really used dry yeast before. Also, had an interesting thought. In order to manipulate yeast character do you think some breweries underpitch for first 24 hrs or so (to increase esters), then on day two pitch other half of the pitch in order for healthy rest of ferment?
I say you'll probably be all right. I've had occasions where I re-pitched dry yeast a couple of days after the first pitch went screwy . . . with no effects that were particularly ill. Suggest you review the mfg's tech data on re-hydrating. My thoughts are no. Yeast esters are most prominently evident during the growth portion of the yeast. Typically underpitching as little as 10% 'ish will boost the esters while not measurably effecting attenuation. The industry doesn't really have a standardized pitch rate so even this concept is variable. I would think a process of trail and error is how most commercial brewers evolve for pitch rate. EDIT: with an Imperial IPA, you should be just fine with hop aroma and alcohol presence dominating the aroma.
In my experience, breweries are much more likely to fuck around with pressure and temp than pitching rates, for yeast character.
