Chill haze formation

Asano, K., Shinagawa, K., and Hashimoto, N. (1982). Characterization of haze-forming proteins of beer and their roles in chill haze formation. /. Am. Soc. Brew. Chem. 40,147-154. 

Such bonding may be sufficient to account for chill haze formation but it is generally believed that the formation of permanent hazes involves oxidation and the production of covalent bonds. 

Another typical enzyme application in the production of beer is the use of proteases, such as papain or laccases in chill-proofing, which is the prevention of haze formation that can occur at low temperatures during or after the maturation of beer. Finally, to... 

At least initially, the protein-polyphenol complexes are held together by weak associations and haze can be dispersed by warming, which in brewing is commonly referred to as reversible haze or chill haze. The practical consequence of this phenomenon is that beer should be bltered at the lowest possible temperature. The mechanism of haze formation appears to be... 

Other enzymes are required to obtain good quality beer with good shelf-life. The major use of non-malt enzymes is an enzyme that is added to fermented beer to chillproof the beer. Beer is fermented and aged under chilled conditions. Almost all packed beer is filtered while cold to achieve clarity. In spite of the filtration steps beer becomes cloudy after it is packed, distributed and chilled again for serving. The cloudiness that develops is caused by formation of haze particles called chill haze which are the result of the interaction between peptides and polyphenol compounds. 

In New Zealand, worts are normally chilled to the point where slush-ice forms. This procedure permits the short storage of wort, but the main advantage appears to be the stability of the derived beers from the point of view of haze formation. 

Asano K, Ohtsu K, Shinagawa K, Hashimoto N (1984) Turbidity formed in beer at low temperatures. Affinity of proanthocyanidins and their oxidation products for hazeforming proteins of beer and the formation of chill haze. Agric Biol Chem 48 1139-1146... 

The addition of 20-30 mg/1 ascorbic acid prevents the formation of colloidal turbidity (called chill haze) in beer, and also prevents adverse changes in flavour due to the oxidation that occurs during pasteurisation and storage. The use of ascorbic acid in winemaking can reduce the amount of sulfur dioxide used for fumigation. 

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