The Oxalic Acid Content in Selected Barley Varieties Grown in Poland, as well as in their Malts and Worts

Abstract

The purpose of this work was to try to answer the question “What factors influence the oxalic acid content in barley, malt and wort?” Samples of three malting barley varieties (Prestige, Sebastian and Jersey, registered and grown in Poland) were investigated for their oxalic acid content. Laboratory scale malting and kilning of these samples and investigation of their oxalic acid content were conducted. Furthermore, the oxalic acid content was analysed in worts obtained from these malts. Tested barley samples, originating from various regions of Poland, showed different oxalic acid contents, ranging from 17.2 to 66.8 mg/kg d.m. basis. A higher temperature of germination (an increase from 14°C to 18°C with the same length of time) resulted in a decrease in oxalic acid content in the resultant worts. In most cases a positive linear correlation was found between the oxalic acid content in the malts and worts, and the initial barley samples. Oxalic acid content in barley appears to depend on the growth region rather than on the variety, but the data was not sufficient to draw any firm conclusions on this subject.