The foaming properties of pale and specialty malts

Received dogma holds that the use of certain specialty malts during the brewing process is to the advantage of beer foam stability. Diverse specialty malts were investigated to determine their foam-promoting and stabilizing capabilities as compared to reference pale malts. The highly kilned specialty malts, Crystal 75L and Crystal 120L, exhibited foam-negative tendencies in untreated extracts. While further assessment of the foam-negative characteristics of Crystal 75L and Crystal 120L by de-fatting and boiling treatment returned improved foam stability values, de-fatting proved inferior to boiling. Extracts were ultrafiltered to separate high and low molecular weight protein fractions and subsequently dosed with extrinsic albumin. This process revealed detrimental foam-negative characteristics in the low molecular weight protein fraction of both Crystal 75L and Crystal 120L. Further proof of the foam-negative impact of Crystal 75L and Crystal 120L malts was demonstrated through introduction of the malts into research pilot brews and the introduction of Crystal 75 and pale malt extracts into commercially available beers. Both the pilot brews and the commercial beer exhibited decreased foam performance with the addition of the specialty malts.