You make beers like those you buy, like those you like. Take a 4.2 % premium bitter, take a 4.5% pale ale, take a 5.6% IPA, take a stout at 4.3 % Find out the hops in each one and the IBU's. Divide the total hop Ibu by 3.5 , that will give you the ballpark aau's , for the bittering hops only for a 60 min boil.