are solid materials that are added to beer, usually after primary filtration, to bind (adsorb) the compounds that produce haze. A range of substances in beer can combine as the beer ages to produce particles large enough to reflect light and cause turbidity. Primary among these substances are polyphenols and proteins.

The most common commercial adsorbents are silica gel, which selectively binds the haze- promoting proteins, and polyvinylpolypyrrolidone (PVPP), which binds polyphenols. PVPP can be used either as a powder or in the form of impregnated secondary filtration sheets. In either instance the PVPP, which is quite expensive, can be regenerated and then reused. Silica gel and PVPP are combined in several commercial products for ease of use. Adsorbents are not considered additives because they are completely filtered out of the beer along with the adsorbed proteins and polyphenols after treatment.

See also silica gel.