Adjuncts are unmalted grains like corn, rice, rye, oats, barley, and wheat. They are primarily used because they offer a cheaper source of extract (a less expensive form of carbohydrate) compared to malted barley, or to modify the flavor of the beer. Adjuncts are employed in the production of light-tasting, light-colored beers with similar alcohol content to most beers.
Uses of Adjuncts
The use of adjuncts results in beers with improved physical stability, superior chill-proof qualities, and greater clarity. The enhanced physical stability is attributed to the fact that adjuncts contribute very little protein to wort and beer, which is advantageous for colloidal stability. Rice and corn adjuncts contribute minimal to no soluble protein to the wort, whereas other adjunct materials such as wheat and barley have higher levels of soluble protein. Except for barley, adjuncts also contribute minimal to no polyphenolic substances.
Adjuncts can be used to adjust the fermentability of wort. Many brewers opt to add sugar and/or syrup directly to the kettle as an effective means of adjusting fermentability, rather than altering mash rest times and temperatures.
Types of Adjuncts
Cereal adjuncts can be added to the cereal cooker, mash tun, or directly to the brew kettle.
Cooker mash adjuncts consist of non-gelatinized cereal products like meal, grits, flour, or dry starch, whose starches exist in their natural forms. A non-gelatinized adjunct requires heating in a separate cereal cooker to complete liquefaction since its starch gelatinization temperature is higher than that used for malt saccharification (starch hydrolysis) temperature. The cooked adjunct is then added directly to the mash in the mash tun.
The adjunct can be mashed directly with the malt in the mash tun in two ways:
When the starch gelatinization temperature of the adjunct is lower than the malt saccharification temperature required for mashing.
When the adjunct has been pre-gelatinized (e.g., for flakes, torrified cereals, and refined starches).
Kettle adjuncts include syrups and sucrose sugar. They are sometimes referred to as “wort extenders” because of the extract they readily provide.