Mixed acid fermentation vs. 2, 3 butanediol fermentation
Mixed acid fermentation produces a variety of acids such as acetic, lactic, and succinic acids which reduce the pH below 4.4 as well as ethanol, carbon dioxide, and hydrogen gas. Butanediol fermentation produces the neutral fermentation products acetoin and 2, 3 butandiol together with ethanol, carbon dioxide and hydrogen gas. Very little acid is produced. The pH is 6.2.