Yeah I guess the main reason why I had it covered was because I just thought it boils alot more vigorously, and quickly. At the time of this batch I hadn't really read anything about DMS and keeping the lid off; my mistake. This batch didn't have any pilsner in it, and also I was opening the lid and venting it quite often. I did hops like every 10 min and probably left off the lid for the last 15 min. I still lost about 1 G of wort in the boil. I've done several pilsner based batches since and have always left the lid off and boiled for 90min... And I used the measuring cup just because I fear that I might drop one of the plastic bags into the wort by accident, ha. Just seemed like it has a better grip. plus sometimes I will mix a few different kinds of hops together in the cup and then add them at the same time. Just a habit.