Irish moss has absolutely nothing to do with partial mashing, it's a coagulant/clarifying agent.
Thanks, I knew that. It just happens to be the two variables I changed from one batch to the next. And I vaguely recall from chemistry class that coagulating/clarifying agents remove things...
I've made 4 batches of IPA, and I'm stumped at how much my OG varies. I always use 6# DME and 1# crystal malt steeped. This time I did a partial mash and added irish moss to the boil. Would either of those changes bring down my OG for 1.052 to 1.042? I also thought it took a long time, 28...