摘要
清酒是利用黃麴菌及酵母菌作用在蒸米上所製作出來一種傳統日式酒精性飲料。製造程序屬於糖化與酒精醱酵作用進行之並行複式醱酵酒。其以精白米、酒母、米麴與水為原料於低溫下進行酒精醱酵。再經壓榨、澄清過濾、殺菌及熟成後，酒液酒精濃度約達20%（v/v）。而清酒釀製原料中之稻米是國內栽培面積最廣的產業。為加強米製品 加工技術，提升國產稻米附加價值，釀製清酒是替台灣稻米找尋出路的因應對策之一。 本研究目的為以國產不同品種稻米為原料找尋醱酵清酒之優良菌株，並探討釀製之清酒進行氣相（GC）色層分析，得到主要香味成份為︰Ethyl acetate、Butyl acetate、Ethyl lactate、Isobutyric acetate、Isoamyl acetate、Ethyl alcohol、Propyl alcohol、Isobutyl alcohol、Isoamyl alcohol、Phenylethyl alcohol等，經比較日本高級清酒發現主要的香味成份皆類似，只是含量彼此之間有一些差異。試釀收得清酒的酒精度可達15%以上，而吟釀香的主要成份Isoamyl acetate 達到1.73ppm。本研究使用的酵母為日本協會九號與日本協會六號酵母，使用的麴菌為BCRC30428，經比較自釀清酒與日本清酒的風味發現，自釀的六號酵母清酒果香較濃郁(Phenylethyl alcohol)，而九號酵母有日本清酒的吟釀香。沒有精米過的池上米酸度比有精米過的高雄139號米的酸度高。沒有精米過的釀造清酒有辛酸乙酯（Ethyl Octanoate）的成份。本實驗發現若是要釀造與日本清酒一樣風味，那可以選擇九號酵母及精白度高的高雄139號的有機米。
關鍵字
清酒並列摘要
Sake is a traditional alcohol beverage of Japan produced from steamed rice by use of Aspergillus oryzae and Saccharomyces cerevisiae. Sake brewing process is a combination of saccharification and fermentation proceeded simultaneous. The polished rice, rice koji, yeast starter (called moto) and water were mixed to become mash (called moromi) at low temperature. The moromi is then pressed, filtered, and the sake was further pasteurized and aging. The alcohol content of sake can be as high as 20 % (v/v). Rice was the most important raw materials of sake. Rice was also the most popular crop in Taiwan. Sake brewing can increase the value of rice. This is one of the strategies to consume local rice production. In this report, we present the processes of making high quality sake that include rice species selection, strain choosing and fermentation exploration. The flavors of sake included ethyl acetate, butyl acetate, ethyl lactate, isobutyric acetate, isoamyl acetate, ethyl alcohol, propyl alcohol, isobutyl alcohol, isoamyl alcohol, phenyl ethyl alcohol, etc. We found very similar flavor pattern in this study as comparing with those from several commercial Japanese sake. The alcohol concentration of sake of this study was 15 %. The flavor of ginjo-shu (isoamyl acetate) of sake for this study was 1.73 ppm. The sake from yeast (Kyokai No 6) was intensively fruity flavor (phenylethyl alcohol). The sake from yeast (Kyokai No 9) has apparent ginjo-shu flavor. The acidity of sake from polished rice was less than that of unpolished rice. The sake from unpolished rice has a ethyl octanoate flavor that was not found from commercial Japanese sake. The conclusion was to brew high quality sake must use polished rice and Kyokai No 9 yeast.