PURPOSE: To obtain an edible vinegar of stable quality with prevented formation of secondary precipitates, production of cloudiness and change in brown coloration, by primarily filtering unrefined vinegar after completing acetic acid fermentation, and ultrafiltering the resultant filtrate through a filtering membrane for a specific fractionated molecular weight or below.

CONSTITUTION: An unrefined vinegar prepared by adding (B) seed vinegar and, if desired, (C) a nutrient substance, e.g. acetic acid bacteria to (A) an alcohol- containing raw material solution obtained from rice, grape, etc. as a raw material is subjected to acetic acid fermentation by stationary fermentation, etc., and the resultant fermentation liquor is primarily filtered by a press, etc. t give an acetic acid fermentation liquor, which is then ultrafiltered through an ultrafiltering membrane for ≤50,000 fractionated molecular weight by the cross flow, full flow filtration method, etc., e.g. at 0W50°C liquor temperature under 1W4kg/cm2 feed pressure to give the aimed edible vinegar.