Comparative figure for bitterness are the International Bittering Units, defined as
|Recommended IBU’s for
central European beerstyles:
A usual way for calculating hoppings looks like this. First spot the amount of aroma hops based on the recipe. AA and the short boil will result in a few IBUs. The difference to the IBU-target has to be produced by earlier hoppings. To calculate the necessary amounts, enter AA, boil time and required IBU. Take into account that utilization proceeds until you start chilling. Distinguishing between Knock out wort and Original Wort enables high gravity brewers to consider effects by high extract content and dilution.