I was torn - I planned to dry hop CornucopIPA, but then when the time came (that's today) I got scared to mess with the beer, for fear of infecting it. In the end, I decided I could handle sanitizing the bag, weight, and thief to get the job done. Plus it would allow me to measure the finishing gravity of the beer and taste a sample. My infant son fell asleep and I was ready to get to work.
My original gravity was 1.065. I used US-05 dry yeast, and was BeerSmith predicted a terminal gravity of 1.016. I was expecting maybe even 1.018 or so. To my astonishment, my finishing gravity is 1.014! That makes it 6.7% ABV - cool! But on the other hand, it is really not full bodied enough for me.
The good news is that I have the cause known. I noticed that my brewing thermometer was reading 70 degrees when sitting in my hydrometer sampling jar. The jar is empty, and it has a stick-on LCD thermometer, which is always on target. The LCD said 65 degrees. Thinking back, my boiling wort registered 220 degrees on the thermometer. At the time, I figured it was just a low pressure day or something, and I'm so close to sea level, or maybe wort boils hotter. But now it makes sense. I adjusted the nut on the thermometer down five degrees. Now boiling water today on my stove was 213 degrees (close enough). An ice bath was a nice 32 degrees.
So turns out I have been mashing five degrees cooler than I thought. That means CornucopIPA was mashed in at 147 degrees. No wonder it finished so low in the gravity department. That also means my Presence Holiday Ale mashed at 146 degrees. That one's probably going to end up pretty dry, too. Hey that also explains the overattenuation of Oatquake - it mashed at 145!
I wonder if I could steep some grains and add them at bottling time to add some body... I'll go ask on Northern Brewer's forum.