Adjunct

What is Adjunct? In brewing, an adjunct is any unmalted fermentable or starch source added to the grist alongside, or partly replacing, malted barley. Typical adjuncts include corn, rice, wheat, oats, rye, and various sugars or syrups. Brewers reach for them to cut costs, lighten body, improve head retention, or contribute distinct flavors. They sit at the heart of styles like American Adjunct Lager, but they also appear in stouts, Belgian ales, and countless specialty beers.

Forms and Common Ingredients

Adjuncts arrive in the brewhouse in two physical forms. Solid adjuncts — flakes, grits, flour, and sugar solids — are added to the mash and require enzymatic conversion of their starches. Liquid adjuncts, such as syrups, go straight into the wort kettle, skipping the mash entirely.

Each ingredient brings something specific to the finished beer. Corn, often used as corn syrup, lowers the grain bill cost and is a staple of pale American lagers because it is cheaper than barley malt. Rice lightens body and produces a cleaner, drier profile; Budweiser is one of the largest rice buyers in the U.S. brewing industry. Wheat improves foam retention and adds a tart edge, while oats lend viscosity and silky smoothness thanks to their high protein and beta-glucan content, which is why they are so common in stouts. Rye contributes spicy character and a dramatic boost in head formation. Unmalted barley, by contrast, is usually capped near 10 percent of the grist because its beta-glucan load can cause haze.

Sugar adjuncts cover a wide range — maple syrup, honey, molasses, Belgian candi sugar, and grain syrups — and offer 70 to 100 percent fermentability, making them powerful tools for tweaking strength and dryness. Flavor and spice adjuncts like coriander, juniper, cinnamon, ginger, nutmeg, and fruits also appear in specialty styles, notably in Belgian lambics.

Styles and Regulation

The BJCP 2021 style guidelines formally recognize American Light Lager, Standard American Lager, and International Lager as adjunct styles. These beers are built on two- or six-row barley with up to 40 percent rice or corn — or sugars — making up the rest of the grist. American Light Lager goes a step further, using exogenous enzymes to lighten body and reduce residual carbohydrates even more.

Adjunct brewing has not always been welcome. Under the Bavarian Reinheitsgebot of 1516, any ingredient beyond water, barley, hops, and later yeast was prohibited, effectively banning adjuncts in Germany. Outside Germany, the purity law is now considered antiquated, and brewers around the world treat adjuncts as a legitimate creative palette rather than a shortcut to be apologized for.