Development of a novel directly marketable beer brewed at low temperature in a domestic refrigerator combined with yeast immobilization technology is presented in this study. Separately, freeze-dried wort and immobilized cells of the cryotolerant yeast strain Saccharomyces cerevisiae AXAZ-1 on tubular cellulose were used in low-temperature fermentation (2, 5 and 7 °C). The positive effect of tubular cellulose during low-temperature brewing was examined, revealing that freeze-dried immobilized yeast cells on tubular cellulose significantly reduced the fermentation rates in contrast to freeze-dried free cells, although they are recommended for home-made beer production. Immobilization also enhanced the yeast resistance at low-temperature fermentation, reducing the minimum brewing temperature value from 5 to 2 °C. In the case of high-quality beer production, the effect of temperature and initial sugar concentration on the fermentation kinetics were assessed. Sensory enrichment of the produced beer was confirmed by the analysis of the final products, revealing a low diacetyl concentration, together with improved polyphenol content, aroma profile and clarity. The proposed process for beer production in a domestic refrigerator can easily be commercialized and applied by dissolving the content of two separate packages in tap water; one package containing dried wort and the other dried immobilized cells on tubular cellulose suspended in tap water.

中文翻译：

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利用冷冻干燥原料酿造家用冰箱的技术发展。

这项研究提出了在家用冰箱中低温酿造的新型可直接销售的啤酒与酵母固定化技术的结合。分别将耐低温酵母菌株酿酒酵母的冻干麦芽汁和固定化细胞管状纤维素上的AXAZ-1用于低温发酵（2、5和7°C）。检查了管状纤维素在低温酿造过程中的积极作用，揭示了与冻干游离细胞相比，冻干固定化酵母细胞在管状纤维素上的发酵速率明显降低，尽管建议将其用于自制啤酒生产。固定化还增强了低温发酵时的酵母抗性，将最低酿造温度值从5降低到2°C。在生产高质量啤酒的情况下，评估了温度和初始糖浓度对发酵动力学的影响。最终产品的分析证实了所生产啤酒的感官浓缩，发现二乙酰浓度低，以及改善的多酚含量，香气和透明度。通过将两个独立包装的内容物溶解在自来水中，可以很容易地将建议的家用冰箱生产啤酒的方法商业化和应用。一个包装包含干麦芽汁，另一个干燥的固定化细胞悬浮在自来水中的管状纤维素上。