Brewing of grape vinegar
There are two types of grape vinegar.
One is to use the remaining slag of the wine to make acetic acid fermentation.
When the alcohol is converted into acetic acid, it is called vinegar.
This vinegar is also called wine vinegar.
The other is to directly brew vinegar with fresh grapes.
The specific method of directly brewing vinegar with fresh grapes is to stalk the fresh grapes, break the skin, juice, and then heat the grape juice to evaporate the juice of the grape juice, so as to increase the concentration of the sugar to achieve the effect of concentration, so as to avoid excessive fermentation.
The time and temperature of cooking are different for each vinegar factory.) Then, the concentrated grape juice is placed in a wooden barrel, and it is slowly fermented. After the season temperature changes, the acetic acid bacteria will gradually turn the grape juice into vinegar.
The biggest difference between aged wine and grape vinegar is that the wine is isolated from oxygen, so the barrels are all filled and packaged, and some will be added with sulfur dioxide to avoid oxidation.
However, grape vinegar should leave some space in the barrel of grape vinegar, the wooden barrel will not be sealed, the opening above the wooden barrel is only covered with cloth, let the vinegar contact the air, continue to oxidize the aging, and let the water naturally evaporate. .