Hydroxy fatty acids as indicators for ageing and the influence of oxygen in the brewhouse on the flavour stability of beer

Abstract

The concentration of oxygenated fatty acids, especially of trihydroxy fatty acids, increase noticeable during the storage of the brewing raw materials barley and malt. Measurement of these lipid oxidation products could therefore contribute to the detection of barley and malt freshness and could additionally be a helpful tool for an assessment of storage conditions. By different pilot plant brews the influence of oxygen in the brewhouse on lipid oxidation and flavour stability was measured: A noticeable connection to brewhouse conditions was found, but in some cases this effect was overlaid by yeast and fermentation influences.