The oxidation or secondary fermentation is caused by the influence of various kinds of vinegar bacteria. There are various types of vinegar depending on the raw materials used in the manufacture. Wine vinegar is obtained from souring of grape wine. Cider vinegar is obtained from the fermentation of fruit juices. Malt vinegar is made from starchy materials.
Distilled vinegar is very often a malt vinegar.
In distilled vinegar the alcohol is distilled off the fermented product before it is fermented by the vinegar bacteria. Sugar vinegar is obtained from various sugars such as glucose, different types of molasses. There were screened air vents located in the top part of the container. A starter culture is put into the container, and the fermentation is continued until the acetification is complete. The process will keep repeating itself as long as quality vinegar can still be produced.