CHELATORS AND METAL BUFFERING IN BREWING

Abstract

The distribution of metals in wort seems to be as important for the brewing process as the metal levels alone. Malt samples from the Norwegian EBC trials have been analysed for Ca, Mg, and Zn. The same elements have been analysed in worts made from these malts. The degree of extraction of metals from the grain is calculated, and this information is compared with available analytical data for the malt or wort samples. A constant ratio between metal extracted and the total metal content in malt was established only for Mg, and not for the other two metals. The comparison with other variables did, however, result in significant correlations. A high correlation was found between Zn and amino acids in wort, and between Ca and polyphenols. This indicates that the amino acids and the polyphenols may take an active part in the regulation of these two metals.