Lesson 2 - Hop Biology and Cultivation

This lesson begins our study of hops focusing on both hop biology and cultivation.

Although compared to malt and water, a relatively small quantity is required, hops are an indispensable raw material for brewing beer. As an example, if we brew a 5% abv alcohol lager with a bitterness of 25 International Bitterness Units (IBU), we would use around 16 kg of malt, but only need roughly 70 g of hops per hL! For some beer styles this is considerably more but never as much as malt and water.

The hop is a tall climbing perennial plant, which forms hop cones (the fruit bearing part of the plant); within these cones are the chemical compounds vital for beer flavour. The hop plant resembles the grape vine, however the hop plant’s vines are instead known as bines. Vines have tendrils to attach themselves to supporting structures, while bines wrap their stem around supporting structures in a helix.

The main reason we use hops is to provide flavour. Later, in the unit we consider the other functions of hops, such as its antimicrobial activity and contribution to foam, colloidal and flavour stability. A number of hop cultivation regions across the world, produce a range of hop varieties. Due to ever changing trends and climate change, new varieties are being developed continually.

However, regardless of these changes, hops should ideally: