Gushing is reviewed with particular attention to the nucleole theory. Evidence derived from phenomena comparable with gushing occurring in fields unrelated to brewing is discussed.

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The effect of the addition of a range of monomeric, dimeric and polymeric polyphenols to beer on the rate of haze formation has been examined. Monomeric polyphenols had no significant effect on haze formation. The addition to beer of dimeric or polymeric polyphenols caused a large increase in the rate of haze formation.

A gas-liquid chromatographic method for the estimation of monomeric and dimeric catechin in beer is described. This method has been used to estimate the concentrations of these compounds in a number of beers, which were found to contain 0*5 to 8'0 ppm of monomeric catechin and up to 22*0 ppm of dimeric catechin. Beers bottled with a high level of air in the headspace can have a long shelf-life providing the level of dimeric polyphenols is low. The shelf-lives of beers which contain high concentrations of dimers are very sensitive to the levels of air in the headspace. At the levels found, monomeric catechin has no significant effect on haze whether or not headspace air is present.

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