Citations: Prepared by Maureen Moroney, research scientist, and
Jennie Savits, enology program specialist, Midwest Grape and Wine Industry Institute at Iowa State University, and Aude Watrelot, assistant professor of enology, Iowa State University Department of Food Science and Human Nutrition.
Abstract: Sulfur dioxide (SO2) is an essential additive in winemaking. This chemical largely is used as a food and wine preservative for its antimicrobial and antioxidant properties. It inhibits, and in some cases kills, some yeast and bacteria. SO2 also protects grape must and wine
from oxidation by enzymatic and chemical reactions, and therefore from browning and off-odors. With proper additions, SO2 aids in preserving aromas and provides protection against incidental oxygen and microbial exposure. It must be used in conjunction with sound
winemaking practices, which include stringent cleaning and sanitation protocols and use of inert gases. Learn more in the Iowa State University and Outreach publication Use of Inert Gases, FS52, store.extension.iastate.edu/product/16405, and Cleaning and Sanitation in the Winery, FS42, store.extension.iastate.edu/product/15978.