Vinegar is a dilute solution of acetic acid (CH3COOH) produced through double fermentation of raw materials. The first fermentation uses yeasts to produce ethanol while the second fermentation uses Acetobacter to convert ethanol into acetic acid. The acetic acid concentration in the broth is typically 10-15% (by volume) but can be as high as 21% in special conditions.
High in acid content, vinegar (especially white vinegar) is self-preserving with an almost indefinite shelf life. However, with consumer expectation for a clear product, vinegar is clarified after acetic fermentation to remove suspended solids including Acetobacter and other microorganisms. In this chemically aggressive application, these modules suffer from operational limits that may dramatically reduce service life, therefore increasing operating cost. A solution with exceptional mechanical strength, thermal and chemical stability provided a reliable and durable solution that could withstand long-term exposure to acetic acid.