Foam inhibitors from specialty malts

摘要

Although there are product-to-product differences, the majority of the crystal and caramel malts tested have been shown to have a net destabilizing impact on foam. A foaming test using a model beer has been developed to quantify the magnitude of this inhibitory effect. Lipid analysis using thin-layer chromatography reveals that there are elevated levels of triglycerides in problematic malts. There also appear to be oxidized lipids in the specialty malts, probably produced in the heating stage of malt production with higher levels in more intensely heated products. However some specialty malts, such as black malt, while containing such foam-negative entities, do display superior foaming properties, probably because they develop even more powerful foam-positive components in the severe heating events.