Wine fermenting is one of the earliest forms of alcohol production observed by civilization. Juices from grapes are mixed with yeast and left for five to fourteen days to produce alcohol. The most important factors in wine production are oxygen levels, sugar content, yeast strain, and temperature of fermentation. White wines are fermented around 64⁰F to 68⁰F. Red wines are fermented at higher temperatures around 85⁰F. Bottle fermentation is used in “sparkling” wines. After fermentation, extra sugar and yeast are added to the bottle before corking. This produces the carbonation. Carbonic maceration is a form of wine fermentation that uses whole grapes. Whole grapes are placed in an air tight container allowing for natural decomposition of the fruit and lack of oxygen to create alcohol. Malolactic fermentation utilizes bacteria instead of yeast. This bacteria turns the naturally occurring malic acid into lactic acid. These bacteria can also work with yeast fermentation processes as well.
