The filterability of wort and beer.

Eyben, D. and Duthoy, J.P.

Abstract
The Esser test for predicting the filterability of a beer is briefly described. This test has been used to study the effect of the degree of proteolysis and the content of beta glucans on the filterability of beer. In laboratory scale experiments the addition of the proteolytic enzymes papain or thermolysin to the mash reduced the filtration rate of the wort despite decreasing the viscosity. Pilot scale tests have shown no significant relationship between wort filterability and beta glucan content, addition of beta glucanase did not improve filterability. Good correlations have been obtained between the Esser test of beer filterability and filtration in the brewery. Tests have shown that the presence of a small amount of yeast improves the filterability of a beer while larger amounts decrease filterability. A highly significant relationship was found between yeast concentration in the beer before filtration and the pressure differential in brewery filtrations. Chill haze, in the absence of yeast, considerably reduced beer filterability.
Keywords: beer beta equipment filterability filtration glucan haze laboratory proteolysis wort