Factors affecting the fermentation process of Vietnamese traditional wine ("men la" wine) using "Ba Nang" wine starter

Abstract

“Men la” wine is a traditional wine product of the upland people in Vietnam. The wine is of the cultural essence of the nation, reflecting the current trend of one village one product (OCOP). The "Ba Nang" wine starters are usually made from sticky rice and local herbs. In fact, the use of herbs in traditional wine production has become popular. However, the traditional methods used by the local producers are not standardized. The quality of the wines produced is therefore not stable and wine producers resort to laborious trials and personal experience. The aim of this study was to examine the factors affecting the fermentation process in the production of “Men la” wine using the wine starters of the Van Kieu people in Da Ban, Ba Nang commune, Dakrong district, Quang Tri province, Vietnam. The ratio of yeast to rice, solid fermentation time, temperature, and time of liquid fermentation, as well as some biochemical criteria, were investigated to determine the best parameters for "Men la" wine production. The results showed that the optimal parameters for obtaining the highest quality of wine were: a mixture ratio of wine starter and whole rice of 8g: 1000g; solid fermentation for 4 days at 30 – 32oC; and fermentation for 7 days at 25oC with a ratio of rice ingredients and water of 1:2. The final product contained 4.952% of total sugar, 0.08% of reducing sugar, 0.315% acid, 0.104 g/L amino acid, and 10.61g/100mL of ethanol. The analysis did not detect methanol in the distilled wine products. The finished wine produced on a laboratory scale had a sweet taste equivalent to that of wine, with a flavor that was thought to be superior to the local wine. The alcoholic fermentation time was shortened by 2 days compared with local wine. The resultant "Men la" wine met the National Technical Regulations for alcoholic beverage products (QCVN 6-3:2010/BYT).