Beer Colloid: Studies with Model Systems. M. J. Lewis, D. J. Muhleman, and S. C. Krumland, Department of Food Science and Technology, University of California, Davis, 95616. J. Am. Soc. Brew. Chem. 37:0061, 1979.

Formation of haze in beer is the result of instability of the beer colloid; molecules or minute particles react and aggregate to form the visible particles of haze. Certain model systems, consisting of protein-carbohydrate (eg, papain-propylene glycol alginate), also form hazes with characteristics of pH, concentration, and salt tolerance similar to those of chill haze. When beer is used as a solvent for such models, the haze formed is much less than in an aqueous system or even absent. Iron (Fe⁺⁺⁺) also induces haze in beer but this haze is greater when the beer is diluted and less when propylene glycol alginate is added. Oxygen-induced haze is also inhibited by propylene glycol alginate. These observations suggest that beer contains an inherent haze-preventing factor that may be protein-carbohydrate in character; such a compound could be formed during, for example, kettle boiling. This suggests that although beer can be successfully stabilized by traditional treatments that remove or digest the haze-forming reactants, enhancement of inherent haze stability during processing may be a desirable aid to beer stabilization.

Keywords: Alginates, Beer, Colloid, Haze, Papain, Propylene glycol alginate