The mystery of the low original gravity of my last two beers has been solved! It turns out the 7 gallon brew kettle that Michelle got me is actually a 10 gallon (40 quart) kettle. The last two beers I brewed had lackluster gravities, including my cream stout, whose OG was under 1.030!
After purchasing a 1 gallon jug of distilled H2O, I filled the kettle to 5 gallons and marked a line. The line was half way up the kettle. Do I feel stupid? Yes, I do.
Well, as this new batch starts, the OG should be much closer to the estimated OG. Lets hope it tastes better too!