honey vinegar is the product of double fermentation. the first, resulting in alcohol and accomplished by yeasts, is anaerobic. this is the process in which honey’s sugars are transformed into alcohol, as in the making of mead. the second is known as acetic oxidation, and is aerobic. acetic bacteria oxidize the alcohol, transforming it into acetic acid. the mead is aged in oak casks used three times before, the static-superficial method, the oldest, most ancestral technique. contact with the air is ensured by wide openings and an ample interface inside the barrels, which are not filled to the brim. acetification only takes place on the surface, thanks to a thin film of bacterial flora. the rooms are heated, and so, indirectly, is the fluid.