My norm has been 5 gallons. For the poster who said something about the weight and carrying, I agree and was thinking about this yesterday as I was doing my Blonde Ale. If I had to try and lug 20 pounds or more of soaked grain that would be tough. 10 pounds or so for a 5 gallon batch is not easy either, but doable. I am still trying to get my water amounts, both mash and sparge, right to end up at 5.5 gallons into the fermenter. Have not quite got it yet, but I am close.