So. I've read that wheat beers (particularly hefes) are...vigorous...fermenters. In order to create the appropriate amount of headspace (~30% from my research) and still brew a decent amount of beer, I've increased my volume a little, and split it between two fermenters. This will leave me with a 4 gallon batch and a 3.5 gallon batch, as I have 6 and 5 gallon fermenters, respectively.
I don't have a large enough pot to do a full boil, so once I've got my batch mixed up and extract in and ingredients combined, what is the best way to ensure even mixing of 1) water, and 2) yeast?
Thanks for your help.