I just brewed my second batch of homebrew -- an imperial coffee stout -- in the hope of creating a tasty brew with a high apv. However, according to my hydrometer, my original gravity is only 1.061 at 70%, which seems impossibly low to me. Before brewing, I used the calculator on hbd.org to calculate a potential original gravity. Here's an outline of the recipe:
1 lb. munich
1/2 lb. American chocolate
1/2 lb. black patent
1/2 lb American 75L
9 lbs. ultralight LME
1/2 lb. light DME
1 lb. brown sugar
So, here's the question: why is my original gravity so low? As I said, this is only my second batch of brew, so I'm still learning the ropes. This phenomenon occurred with my first batch as well -- an IPA -- that was supposed to be between 1.046-1.057, but had an OG of 1.031 for me. What am I doing wrong?
Thanks for the help.

