This is my first shot at homebrewing, using Northern Brewer's American Wheat Beer kit which is based on liquid malt extract, Willamette and Cascade hops, and a packet of dry yeast. I brewed and put the hopped wort into fermentation on Friday. By Sunday morning (~40 hours later), fermentation seemed to be moving along at a good clip -- I could see bubbles traveling through the airlock about once every 2 seconds.
However, by Monday morning, bubbling had completely stopped. The weather (and my house) had gotten considerably cooler overnight, so thinking the cold was to blame, I moved the fermenter into the warmest room in the house (which still probably never goes over 70 Fahrenheit). Still, no bubbling as of Tuesday evening.
I was under the impression that fermentation should be vigorous for at least a few days.
I've been doing some research and realize now that when I was brewing I didn't really understand the importance of aerating the wort. I shook it around for a minute or so in the fermenter on brewing day, but maybe that wasn't enough? Also, I didn't realize until brewing day that I should have been keeping the dry yeast packet in the fridge/freezer -- it had been sitting out in my basement (60-75 Fahrenheit) for at least a month. Oops.
Any thoughts on if I screwed something up or if there's a way to fix it (if it really needs fixed)?
I'd appreciate any help. Thanks!
Update: At the suggestion of Denny (and some other homebrewers I talked to in person), I decided to just let the fermentation run its course and I'm happy to report that fermentation seems to have worked -- my original gravity was 1.041 (possibly slightly higher as the reading was taken warm) and after two weeks on bottling day I was at 1.016 = 60% attenuation (right?). Although the Safale US-05 Ale Yeast I used doesn't give attenuation specs, some folks on a forum said they usually get at least 70% from that strain, so it's possible that fermentation might have been a little stunted from the yeast not being refrigerated.
The beer is conditioning in the bottles now, so hopefully it will taste good when I crack one open in a couple weeks. Thanks everyone for all the input -- if nothing else I've learned the importance of taking good care of the yeast.