First, add some pure yeast.

Wine is made by natural fermentation. Therefore, too many stray bacteria and microorganisms, either in the air or in the container, may produce more methanol and heteroalcohol oil. Adding yeast prevents the reproduction of ** bacteria. Thus, reducing the methanol content.

Second, choose fresh grapes. The choice of grapes can lead to poisoning.

Because grapes are sprayed with pesticides during the growing process. So for homemade wine, make sure to wash the grapes. Also, choose fresh grapes. Some people deliberately do not wash them well, saying that it is for the skin microbial fermentation. This practice, is not desirable.

Third, the holding container should be clean, good choice of glass, ceramic and other containers.

In fact, the methanol in the wine, mainly from raw materials. Raw materials in the pectin material decomposition, amino acid deoxygenation and fermentation of raw materials mold, will produce methanol. The longer the fermentation, the higher the methanol content. In other words, the longer the years, the higher the alcohol concentration of home-brewed wine, containing methanol, may also be higher.

In addition, it is difficult for residents to achieve the necessary processes such as filtration and sterilization during the homebrewing process. Therefore, the shelf life of home-brewed wine is shorter.