OK, I could use some help figuring this out. Currently, I do partial mashes with partial boils. I have done mostly 5 gallon batches, but have begun doing more and more 3 gallon batches, which seems to suit me well. I like the ability to use a higher percentage of grain.
I know that the inability to brew with a full boil limits any venture into AG, but I'm thinking I could get away with it for 3 gallon batches and a mash with no sparge. I figure I can get my 2.5 gallons of first runnings to the proper OG without extract and then top off to 3 gallons in the fermenter like I would normally.
However, I really don't know how to start figuring it all out. When I do partial mashes, I use about 1.3 qts/lb for the mash. At this ratio, I could mash something like 6-7 pounds of grain and get 2.5 gallons of first runnings (after accounting for loss to grain absorption).
But the more I think about it, the more I realize that I have no idea how to dial this in. How do I estimate a gravity with no sparge? How do I hit a 1.060 vs a 1.040? Do I adjust the water:grain ratio? Is doing something like this possible or advisable? Any and all help would be greatly appreciated.