Abstract: Disclosed herein is a process for producing vinegar of favorable flavor exhibiting inherent flavor, taste and color derived from starting material, comprising the steps of bringing vinegar derived from fruits, etc. into contact with a non-ionic porous synthetic adsorbent, selectively adsorbing to remove iso-valeric acid contained in vinegar and reducing the concentration of iso-valeric acid to below 10 ppm, thereby effectively removing uncomfortable smelly ingredient, while leaving soluble nitrogen ingredient as the tasting or ingredient, organic acids providing mild sourness and color ingredients.

Abstract: The present invention is based on the finding that peculiar odors in rice vinegar are derived from organic acids and nitrogen derivatives, etc. formed upon production and it concerns a process for producing rice vinegar of enriched flavor, wherein the amount of peculiar odor-forming organic acids formed in the production step of the rice vinegar is as little as possible and a treatment for removing nitrogen compounds is applied and gluconic acid is added.

Abstract: A process for producing vinegar is disclosed wherein cereals or fruits are subjected to alcoholic fermentation thereby resulting in an alcohol fermentation product which is subsequently purified by ultra-filtration membranes to obtain purified alcohol. The purified alcohol is subjected to acetic acid fermentation and vinegar is recovered therefrom.