Hey all. First time posting here and somewhat new to brewing. I've got 3 extract recipes under my belt and wanted to give partial mashing a shot, which I did last night. Researched the bejesus out of this before tackling, and thought I had it all figured out, but I ended up missing my target OG by 13 points and I'm not sure why. Hopefully someone can help me figure this out before my next go. Here's my grain bill: 4# - German Wheat Malt 1# - American 2 Row .5# - Carmel/Crystal 10L 6# - DME (Golden Light) When I plugged these numbers into the BF recipe calculator, I got an OG estimate of 1.050 using a somewhat conservative 60% efficiency (which was my hope). My end result was 1.037 which is an efficiency rate of 30%. Here's the process I used. I mashed the grains at 152 degrees for an hour, using 6.5 quarts of water. It held at this temp pretty well as I put the kettle in the oven for the full hour. I should mention, I used a 5 gal paint strainer bag in the kettle and mixed up the grains really well. I let the grains drain before doing a batch sparge in another 6.5 quarts of water heated to 180 degrees. My pre-boil volume was about 2.8 gallons, that was before adding my DME (didn't measure my volume at this point - wish I would have). Post-boil volume was slightly over 2.5 gallons. Ended up having 2 quarts of waste in the kettle before going into the fermentor. I think those are the key things. I have a feeling I may not have used enough water in the mash, or the paint strainer bags aren't big enough. Would really like to get some feedback from the experts, as I've become somewhat addicted to this hobby, and I don't want to be frustrated when I do my next brew.