荔枝香甜酒製程之研究

Abstract

本研究以“黑葉”種荔枝為原料製成荔枝香甜酒。進行以下實驗（1）分別以荔枝果汁與稀釋一倍之果汁加糖至22°Brix做為荔枝酒與蒸餾原料酒之原料，發酵溫度25℃下，進行酵母菌與發酵基質中SO2濃度與檸檬酸添加量的篩選；（2）以95 ％酒精強化荔枝酒至18 ％，建立最適之調配配方與熟成條件；（3）探討來自不同原料酒與蒸餾方式之荔枝蒸餾酒精，香氣成分之變化與其做為荔枝香甜酒蒸餾酒精的適合性。 結果顯示，荔枝酒之發酵基質中添加200 ppm SO2，宜以檸檬酸2~3 g/L調整酸度（此時pH小於4.76）後，接種酵母菌Saccharomyces cerevisiae Danstil D或Lalvin V1116進行發酵。荔枝香甜酒之配方為添加酒液量1/4或1/2倍之荔枝果汁，調整最終糖酸比為60∼80，其於25或16 ℃熟成並無差異。剔除酒頭（酒醪量1 ％）及酒精度5 ％以下之酒尾後可得酒精度為40％之初蒸液。初蒸液直接複蒸或稀釋一倍再行複蒸，剔除酒頭後取酒精度70 ％以上做為蒸餾酒精，酒精度各為76.2 ％與73.8 ％，酒精回收率皆在五成以上。蒸餾原料酒以及蒸餾酒精香氣成分中，皆以異戊醇含量最多，且稀釋複蒸者含量高過直接複蒸者。品評結果顯示，發酵基質中添加75 ppm SO2及5 g/L檸檬酸釀製之原料酒，經初蒸後直接複蒸，為荔枝香甜酒之蒸餾酒精的最適製程。

The lychee dessert wine in this study is made from “Hei-Yeh”variety. We discuss：Lychee puree as itself for lychee wine fermentation or diluted with equal amount of water for lychee wine-spirit base wine fermentation were adjusted to 22 °Brix by the addition of sugar. Citric acid was added to acidify the must. Various yeast srains were inoculated to ferment the must contained 200 ppm SO2 at 25℃. To select the suitable formulation and aging condition, the 18% lychee dessert wine fortified by 95% alcohol was used. The sensory evaluation of lychee dessert wine and the aroma analysis were performed to demonstrate the effect of the type of wine-spirit base wine and the way of distillation. The results show that the addition of citric acid at 2~3 g/ L, and the inoculation of Saccharomyces cerevisiae Danstil D and V1116 were suitable for lychee wine fermentation. Danstill D was the best yeast strain for the fermentation process in wine-spirit base wine. A suitable formulation for 18 % lychee dessert wine is to mix the lychee wine with lychee juice at 4：1 ~2：1 ratio. There are no differences between the 16 and 25℃ aging temperatures. In the firs distillation, discard the first 1% of the volume of the batch and collect all the distillate with an alcohol content higher than 5%. The brouillis produced is at 40 %. During the second distillation, discard the first 1% of the volume of the bath, and collect all the distillate with an alcohol content higher than 70%. The wine-spirit from the brouillis distillation is at 76.2 % alcohol content and that from the brouillis diluted with equal amount of water is at 73.8 % alcohol content. Their recoveries in ethonol are higher than 50 %。The two kinds of distillate were used as the lychee wine-spirit in fortification. The major aroma compounds of the lychee wine-spirit base wine, brouillis and wine-spirit is 3-methyl-1—butanol. The content are higher in the wine-spirit from the diluted broullis than that from the brouillis. When the SO2 concentration is at 75ppm, the addition of citric acid at 5 g/ L is suitable for lychee wine-spirit base wine fermentation. The wine-spirit distilled from the brouillis is a proper wine-spirit for lychee dessert wine making.