Distilled White Vinegar in a Packed Generator

"Distilled" white vinegar is not distilled vinegar: it is vinegar fermented from distilled alcohol. Sugar is first fermented to alcohol and distilled; acetic acid bacteria then turn the alcohol into acetic acid. In 1823 Karl Sebastian Schüzenbach in Baden built the packed generator, which circulates the alcohol over beechwood shavings and cut the fermentation from months to one or two weeks; it made vinegar from pure alcohol practical. The finished vinegar is diluted to a colourless 5–8% acetic acid in water, pH about 2.6, used in cooking, pickling and cleaning.