Wormwood is used today mainly as a bitter tonic and so it is perfect to use as a bittering agent for your beer or gruit. Use this sparingly. We recommend 1/2 ounce / 5 gallon batch. Even 1/4 ounce may suffice!
Tip: Fun fact "as bitter as Wormwood" is a very Ancient proverb, and is also mentioned in Biblical texts "her end was as bitter as wormwood. Hope that is bitter enough for you hopheads.