So I’m working backwards on this a bit, but here’s my predicament:
I brewed a Patersbier on Sunday using a single smack pack of Wyeast 3787, (note, I bought it the same day, and I was in a hurry to get everything done and brewed on Sunday). The manufacturing date on the pack was December 13th, which had me concerned that the viability would require an additional smack pack or a starter. When I asked the guy at the NB Milwaukee store if I needed a few additional packs due to the age of the yeast, he didn’t seem to know what I was talking about, and just assured me that a low gravity beer like a Patersbier (OG = 1.046) would be fine with only one smack pack.
I brewed Sunday, and I have about a 3 inch layer of Krauesen forming as of today, with relatively low airlock activity (I know these aren’t necessarily reliable indicators of attenuation). My concern is that I checked the yeast viability on Mr. Malty’s website today, and lo and behold, it was only at 30%! According to their pitch rate calculator, I would have needed more than 4 of these smack packs, or 2 starters, to have the proper pitch rate. Should I add several more smack packs and/or a starter at this point, or wait to take a gravity reading in about 10 days? I would prefer to avoid wasting additional weeks if I can.
Any feedback, as always, is appreciated!