I'm on my 5th partial mash brew and I'm looking to do a stout. I have a 4 gallon pot that I figure can handle roughly a 6 lb grain bill. Problem is the recipes I'm looking at all have about 4.5 lbs of specialty grains and I've read that the base grain to specialty grain ratio should stay 1:1. Is this a pretty steady fast rule? What would happen if I were to mash with 4.5 lbs of specialty grains and say 2 pounds of base grains?