Brew Kettle & Hops

The wort goes into the kettle and comes to a rolling boil. The boil does several jobs at once: it sterilises the liquid, destroys the enzymes and so locks in the sugar profile, drives off unwanted aromas, and concentrates the wort to the target strength as water evaporates.

Above all, this is the moment for hops. When we add them matters as much as how much we add.

Hops added at the start of the boil cook for a full 60 to 90 minutes. Their acids convert into a soluble, bitter form — these are bittering hops. Hops added in the final minutes don't boil long enough to bitter, so their volatile essential oils survive instead: floral, citrus and fruity aroma. These are aroma hops.

That's why an IPA bursting with fruit aroma often gets most of its hops near the end of the boil — or even after it.