Brewing Yeast Research Group, Centro de Biotecnologia da Universidade Federal do Rio Grande do Sul, Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Food Res Int. 2021 Mar;141:110125. doi: 10.1016/j.foodres.2021.110125. Epub 2021 Jan 9.
Yeasts from the species Saccharomyces cerevisiae (ale yeast) and Saccharomyces pastorianus (lager yeast) are the main component of beer fermentation. It is known that different beer categories depend on the use of specific ale or lager strains, where the yeast imprints its distinctive fermentative profile to the beer. Despite this, there are no studies reporting how diverse, rich, and homogeneous the beer categories are in terms of commercially available brewing yeast strains. In this work, the diversity, richness, and evenness of different beer categories and commercial yeast strains available for brewing were evaluated by applying quantitative concepts of diversity analysis in a sample of 119,189 beer recipes. For this purpose, the frequency of ale or lager and dry or liquid yeast formulations usage was accessed and its correlation with the number of yeast strains, recipes, lowest and highest values of original and final gravity, international bitter units, and alcohol by volume were analyzed. A statistical framework was applied for comparing the lowest and highest fermentation temperature as well as the attenuation percentage for ale and lager yeasts strains in both dry and liquid formulations. Additionally, the brewer's preferential use of a specific brewing yeast strain in comparison to all different yeast strains reported for a beer category was estimated. The results indicated that many beer categories are preferentially fermented with dry yeast formulations instead of liquid yeasts, despite the high number of available liquid yeast formulations. Finally, the preferential use of specific yeast formulations drives the fermentative diversity of a beer category, showing that many yeast strains are potentially and industrially underexplored.
酵母属的酿酒酵母（Ale 酵母）和发酵酒香酵母（Lager 酵母）是啤酒发酵的主要成分。众所周知，不同的啤酒种类取决于使用特定的 Ale 或 Lager 菌株，其中酵母会给啤酒打上独特的发酵印记。尽管如此，目前还没有研究报告商业上可用于酿造的啤酒酵母菌株在啤酒种类方面的多样性、丰富度和均一性。在这项工作中，通过在 119189 个啤酒配方样本中应用多样性分析的定量概念，评估了不同啤酒种类和商业可用酿造酵母菌株的多样性、丰富度和均匀度。为此，评估了 Ale 或 Lager 和干酵母或液体酵母配方的使用频率，并分析了其与酵母菌株数量、配方数量、原始和最终比重、国际苦度单位和体积酒精度的最低和最高值的相关性。应用了一个统计框架来比较 Ale 和 Lager 酵母在干酵母和液体酵母配方中的最低和最高发酵温度以及衰减百分比。此外，还估计了与啤酒种类中报告的所有不同酵母菌株相比，酿酒师对特定酿造酵母菌株的优先使用情况。结果表明，尽管有大量的液体酵母配方可用，但许多啤酒种类更倾向于使用干酵母配方进行发酵，而不是液体酵母。最后，特定酵母配方的优先使用驱动了啤酒种类的发酵多样性，表明许多酵母菌株具有潜在的和工业上的未充分开发性。
