酿酒中的酵母

酵母在酿酒中有重要作用，是区别葡萄酒和葡萄汁的重要因素。在無氧的情况下，酵母通过发酵将葡萄的糖分转化为酒精和二氧化碳。葡萄中的糖分越多，葡萄酒的潜在酒精含量就越高^[1]。有时酿酒师会提前停止发酵，以便在葡萄酒中留下一些残余的糖分和甜味，如甜酒^[2]。这時可以将温度降低使得酵母不再活跃。如果发酵无意中停止，此時會被认为是出現了發酵停滯^[3]。

酵母種類编辑

當夏多內葡萄酒因含有太多丁二酮而帶有奶油味時，釀酒師可能加入更多酵母，將丁二酮還原成無味的2,3-丁二醇

最常用於釀酒的酵母種類是釀酒酵母，其發酵能力強且易於預測，並能在酸性、酒精與二氧化硫濃度高的環境生長。通常釀酒時有不只一種酵母菌參與，許多葡萄會自帶有孢漢遜酵母屬與念珠菌屬的酵母菌^[4]，但當酒精濃度超過約15%時，這些酵母菌會因無法耐受酒精而死亡，而由酵母屬的酵母菌繼續進行發酵，例如貝酵母（英语：Saccharomyces bayanus）在酒精濃度17%至20%的環境仍能生長。另一類群的酵母菌酒香酵母有時被視為危害酒的品質，有時被認為對酒提供了特殊風味^[5]。其他常參與釀酒的酵母菌還包括酵母屬的巴氏酵母（英语：Saccharomyces pastorianus）與葡萄汁酵母等，以及類酵母屬、裂殖酵母屬、接合酵母屬以及金黃擔子菌屬的類群^[2]^[3]^[4]。

產物编辑

酵母菌釀酒時的副產物包括甘油、甲醇、雜醇油、琥珀酸、乙酸、乙醛、硫化氫與丙酮酸等，影響酒的氣味與顏色^[4]^[6]。

参考文献编辑

^ D. Bird "Understanding Wine Technology" pp. 67–73 DBQA Publishing 2005 ISBN 1891267914
^ ^2.0 ^2.1 Jeff Cox "From Vines to Wines: The Complete Guide to Growing Grapes and Making Your Own Wine" pp. 133–36 Storey Publishing 1999 ISBN 1580171052
^ ^3.0 ^3.1 J. Robinson (ed) "The Oxford Companion to Wine" Third Edition pp. 778–80 Oxford University Press 2006 ISBN 0198609906
^ ^4.0 ^4.1 ^4.2 K. Fugelsang, C. Edwards Wine Microbiology Second Edition pp. 3–28 Springer Science and Business Media , New York (2010) ISBN 0387333495
^ B. Zoecklein, K. Fugelsang, B. Gump, F. Nury Wine Analysis and Production pp. 281–90 Kluwer Academic Publishers, New York (1999) ISBN 0834217015
^ Yair Margalit, Winery Technology & Operations A Handbook for Small Wineries pp. 67–74 The Wine Appreciation Guild (1996) ISBN 0932664660

[Bird-1] D. Bird "Understanding Wine Technology" pp. 67–73 DBQA Publishing 2005 ISBN 1891267914

[cox-2] 2.0 ^2.1 Jeff Cox "From Vines to Wines: The Complete Guide to Growing Grapes and Making Your Own Wine" pp. 133–36 Storey Publishing 1999 ISBN 1580171052

[Oxford_pg_778–780-3] 3.0 ^3.1 J. Robinson (ed) "The Oxford Companion to Wine" Third Edition pp. 778–80 Oxford University Press 2006 ISBN 0198609906

[Wine_Micro_pgs_3-28-4] 4.0 ^4.1 ^4.2 K. Fugelsang, C. Edwards Wine Microbiology Second Edition pp. 3–28 Springer Science and Business Media , New York (2010) ISBN 0387333495

[Zoecklein_pgs_281-290-5] B. Zoecklein, K. Fugelsang, B. Gump, F. Nury Wine Analysis and Production pp. 281–90 Kluwer Academic Publishers, New York (1999) ISBN 0834217015

[Yair-6] Yair Margalit, Winery Technology & Operations A Handbook for Small Wineries pp. 67–74 The Wine Appreciation Guild (1996) ISBN 0932664660

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