Ohio Rev. Code § 3715.31: Malt vinegar.

Vinegar manufactured, offered or exposed for sale, sold, or delivered, or in the possession of a person with intent to sell or deliver, under the name of malt vinegar shall be the product made by the alcoholic and subsequent acetous fermentations, without distillation, of an infusion of barley malt or cereals whose starch has been converted by malt, is dextrorotatory, and shall contain in one hundred cubic centimeters, at a temperature of twenty degrees centigrade, not less than four grams of acetic acid, not less than two grams of solids, and not less than two-tenths grams of ash. The water-soluble ash from one hundred cubic centimeters, at a temperature of twenty degrees centigrade, of the vinegar shall contain not less than nine milligrams of phosphoric acid (P2O5) which shall require not less than four cubic centimeters of decinormal acid to neutralize its alkalinity.