The microbiome of Sardinian barley and malt

The microbiology of barley and malt (var. ‘Scarlett’) used by a Sardinian brewery is reported. Isolates of bacteria (95), yeast (22) and filamentous fungi (137) were identified through classical and molecular methods. Malt showed higher biodiversity than barley, as shown by Shannon–Wiener's and Simpon's Dominance Indices. There was no contamination by microbial species that can influence barley germination or cause beer defects, such as gushing or premature yeast flocculation. There were low levels of contamination by the filamentous fungi Fusarium, which produce type A and B mycotoxin trichothecenes. However, deoxynivalenol, T-2 and HT-2 mycotoxins were all below the maximum levels for contamination of foodstuffs. Use of locally cultivated barley can help in the management of microbial spoilage of grain and malt, and in the reduction of mycotoxins, thus providing better beer quality. © 2018 The Institute of Brewing & Distilling.