Hop Character-Boil Times
This interactive chart shows the effects different boil times have on hops. A short boil time will release more aroma from the hops, peaking at about 7 minutes. A slightly longer boils departs more flavor with peak flavor at about 20 minutes. At about 15 minutes the bitterness of the hops (alpha acids) start to show up and continues to rise past the 60 minute mark. After 60 minutes bitterness can continue to rise but at a much slower rate.
Hover your mouse over each of the graphs to see the percentage/times for each characteristic.
