Acetic Acid as a Causative Agent in Producing Stuck Fermentations

Sample lots of 1993 Chardonnay grape juice and Merlot must with skins were fermented in duplicate lots under controlled temperature using techniques common to commercial winemaking. At mid-fermentation, four levels of acetic acid were introduced to simulate fermentative acetic acid spoilage independent of other bacterial metabolism. Effects on fermentation rate are reported. An hypothesis for the mode of action of acetic acid toxicity is proposed.