De novo sourdough cultures were here assessed for their potential as sources of yeast strains for low-alcohol beer brewing. NGS analysis revealed an abundance of ascomycete yeasts, with some influence of grain type on fungal community composition. Ten different ascomycete yeast species were isolated from different sourdough types (including wheat, rye, and barley) and seven of these were screened for a number of brewing-relevant phenotypes. All seven were maltose-negative and produced less than 1% (v/v) alcohol from a 12 °Plato wort in initial fermentation trials. Strains were further screened for their bioflavouring potential (production of volatile aromas and phenolic notes, reduction of wort aldehydes), stress tolerance (temperature extremes, osmotic stress and ethanol tolerance) and flocculence. Based on these criteria, two species (Kazachstania servazzii and Pichia fermentans) were selected for 10 L-scale fermentation trials and sensory analysis of beers. The latter species was considered particularly suitable for production of low-alcohol wheat beers due to its production of the spice/clove aroma 4-vinylguaiacol, while the former showed potential for lager-style beers due to its clean flavour profile and tolerance to low temperature conditions.

在此评估了从头发酵培养物作为低酒精啤酒酿造酵母菌株来源的潜力。NGS分析显示，大量的子囊酵母，对谷物的真菌组成有一些影响。从不同的面团类型（包括小麦，黑麦和大麦）中分离出十种不同的子囊酵母菌种，并筛选了其中的七种与酿造相关的表型。在最初的发酵​​试验中，全部七个都是麦芽糖阴性的，并且从12°Plato麦芽汁中产生的酒精含量不到1％（v / v）。进一步筛选了菌株的生物风味潜力（产生挥发性香气和酚醛香气，减少麦芽汁醛），耐应力性（极端温度，渗透压和乙醇耐受性）和絮凝性。根据这些标准，两个物种（选择了Kazachstania servazzii和发酵毕赤酵母（Pichia fermentans）进行10次L规模的发酵试验和啤酒的感官分析。后者由于其生产的香料/丁香香气4-乙烯基愈创木酚被认为特别适合于低酒精度小麦啤酒的生产，而前者由于其干净的风味和对低温的耐受性而具有更大啤酒的潜力。条件。