Hops A-Z; A is for Aroma

Think about the first time you lifted a beer to your nose and felt its bouquet pervade your nostrils. Or when you've held hop flowers in your hands, rubbed them between your fingers and released their sticky scent. When you've walked into a brewery and the air was filled with flowers and fruits. The sheer joy of hop aroma.

It's a volatile commodity, though. The essential oils in a hop cone have a hydrocarbon fraction comprised mainly of the aromatic monoterpene, myrcene. Broken down by the boiling wort in a process called thermal isomerisation, only a minority percentage of those oils remain present.

So the aroma profile of beer is bolstered by adding hops towards the end of the brewing process. That could be either directly into the copper (late hopping), infusing the hot wort as it travels to the cooler (via a hop back) or adding them direct to the fermenter or barrel (dry hopping).

The result can be a harmonious gathering of ripe citric fruits or summer meadow flowers. Or it could be a big fat nose-stinging-oh-my-god-I'm-having-a-nose-bleed mess. Sometimes brewers can be heavy-handed, albeit with the best intentions. I like a beer's aroma to be alluring - a fleeting glimpse of bra strap rather than a flash of boobs. Subtle aroma isn't yet an endangered species in craft brewing and I'm hoping that it'll stay that way.