Mixing Vinegar, Alcohol, and Starter
An optimal acetic acid - alcohol ratio ensures a clean fermentation start.
Whether surface, generator, or submerged process, the initial mixture to start a vinegar fermentation should contain a certain amount of acetic acid or rather vinegar to avoid off-taste and moldy smell. The heightened acetic acid content protects against most kinds of unwanted microorganisms and vinegar eels. Alcohol is food for the vinegar bacteria. A solution with 4 % acetic acid and 2 % alcohol has proven the most effective mixture in practice.