GENERAL COMPOSITION OF NON-BIOLOGICAL HAZES OF BEERS AND SOME FACTORS IN THEIR FORMATION. PART I

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Abstract
A study has been made of the chemical composition of chill-hazes and oxidation-hazes of certain commercial and experimental beers. In addition to amino acid and sugar units, the hazes have been shown unequivocally to contain tannin derived both from malt and from hops. The hazes have been shown to be heterogeneous both by means of chemical fractionation and by ultracentrifugation. Spectrographic examination of the ash from certain specimens revealed that the hazes contained concentrations of heavy metals, particularly copper, iron and aluminium, which were high relative to their concentrations in the beers giving rise to them. The study was extended to include some factors which affect the rate of formation of hazes in beers. Heating of hazy beers resulted in solution of the haze already present slowly followed by the precipitation of a further haze with solubility characteristics different from those of the original. The effect of cooling beers which had been heated for a brief period at 70° C. was also studied. It was found that the rate of formation of haze was lower after rapid cooling of the beer than after slow cooling. Finally, the rate of formation of haze was, within limits, independent of the amount which had already separated from solution, suggesting that there is a considerable reserve in the beer of potential haze constituents.

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