Adjuncts are unmalted grains (such as corn, rice, rye, oats, barley, and wheat) used in brewing beer which supplement the main mash ingredient (such as malted barley), often with the intention of cutting costs, but sometimes to create an additional feature, such as better foam retention.
Read more about Adjuncts: Definition, Types of Adjuncts and Adjunct Products, Sources of Starch Adjuncts, Sugar Adjuncts, Flavourings, Fruit or Vegetable Beer