大麥芽與啤酒花及酵母對精釀啤酒釀造之影響

Effects of Barley Malt, Hops, and Yeast, on the Quality of Craft Beer Brewing

本研究探討利用不同大麥芽、啤酒花與酵母釀造之八種啤酒，進行其成分分析與官能品評。用兩種大麥芽（Pilsen和Vienna）、兩種啤酒花（Cascade和Hallertau Tradition）以及兩種酵母（愛爾酵母（Ale yeast, Fermentis T-58）與拉格酵母（Lager yeast, FermentisS-23））以15℃進行一次發酵，24天後添加蔗糖並裝瓶，於15℃下進行瓶內發酵30天。維也納大麥芽處理組的啤酒泡沫持續時間較長。而在下層發酵的拉格酵母處理組之酒損率較低，酒液透光度較佳，酵母發酵率較高，於瓶內發酵階段pH值較低，且官能品評結果在香氣、口感、與苦味指數都較上層發酵的愛爾酵母處理組好。本研究啤酒中醇類物質僅偵測到乙醇，而甲醇、異丁醇、正丙醇、正丁醇、異戊醇與苯乙醇皆低於偵測極限（0.01%）。 The study used two barley malts (Pilsen and Vienna), two hops (Cascade and Hallertau Tradition) and two yeasts (ale yeast (Fermentis T-58) and lager yeast (Fermentis S-23) ) to brew eight types of beer and to analyze the differences among them through chemical and sensory analysis. The primary fermentation of those beers was conducted for 24 days at 15℃. At the bottle conditioning stage, sucrose was added to undergo fermentation in the bottle at 15℃ for 30 days. The beer made from Vienna malt showed a longer beer head foam retention time. Through the use of bottom-fermenting lager yeast, it had lower beer weight loss rate as well as higher transmittance, lightness and yeast attenuation. The pH value was also lower than others during the bottle conditioning stage. According to the result of sensory evaluation, lager beer was better than ale beer at aroma, taste, and bitterness score. Ethyl alcohol was the only alcohol found in beers among all samples. Methyl alcohol, isobutyl alcohol, 1-propyl alcohol, n-butyl alcohol, isoamyl alcohol, and 2-phenylethyl alcohol were not detected at the detection limit 0.01%.