What Are Hops? The Science and Soul of the Industry

Hops are the heart of the brewing world, but they are also a marvel of agricultural history. While many people recognize the distinctive aroma of a craft IPA, few realize that these powerful little cones come from a vigorous, climbing perennial plant known as Humulus lupulus.

The yellow powder called the lupulin is the source of the hop's bittering acids and essential oils.

The Botany of the Hop

Hops are actually the flowers—often called seed cones or strobiles—of the female hop plant. As a herbaceous perennial, the plant is a "biner" (climbing by wrapping its stems around a support) rather than a "vine" (which uses tendrils).

Whether you call the field a hop yard (U.S. and West Country), a hop garden (South of England), or a hop field, these plants are a sight to behold, often trained to grow up strings reaching heights of nearly 20 feet in a single season.

Why Hops Are Essential to Beer

Hops provide the essential balance. They act as:

• A Flavoring Agent: Imparting the bitter, zesty, or citric flavors we love.

• A Stability Agent: Providing natural preservative qualities that help beer stay fresh.

• A Balancing Force: Cutting through the sweetness of the malt to provide depth and "zest."

The Evolution of the Industry

Throughout history, brewers have experimented with various plants to balance their brews, but hops eventually took center stage. In recent decades, West Coast microbrewers revolutionized the industry by creating hop-forward beers where the plant’s character—bitter, piney, grassy, or floral—is the main attraction.

This gave rise to the popularity of IBUs (International Bittering Units), a measure of the concentration of hop compounds. Today, there is a stunning array of varieties, with new breeds being developed constantly to create the next generation of flavors.