Types of Fermentation That Produce Beer & Wine

Beer and wine are made with the same general process

While beer and wine may taste completely different, they are produced by the same fermentation process. Alcoholic fermentation is a surprisingly simple process that converts sugar into alcohol and CO2. Although the process of fermentation is the same for both beer and wine, the materials used and time needed can vary drastically.

Alcoholic Fermentation

Alcoholic fermentation converts sugars into carbon dioxide and ethyl alcohol. This is done by adding yeast to a substance rich in carbohydrates. The yeast actually eats the sugar, which reduces the overall sugar content of the finished alcoholic beverage. The carbon dioxide that is created during the fermentation process is released into the air while the alcohol remains in the beverage. The type of alcohol created in alcoholic fermentation is referred to as ethanol.

Yeast

There are many strains of yeast that are used in beer and wine. Each strain of yeast imparts a unique flavor to the alcoholic beverage. Each type of yeast also has specific alcohol tolerances. On average, beer yeast can only tolerate 5 percent ethanol while wine yeast can tolerate 12 percent. These numbers can fluctuate greatly depending on the type of yeast used. Yeast also relies on a certain temperature during the fermentation process. Once again, this varies based upon the strain of yeast used.

Wine Ingredients

When wine is created, yeast is added to grape juice and allowed to ferment. Wines typically have an alcohol content of about 12 percent, depending on the sweetness of the grape used and the style of wine that is desired. To make red wine, winemakers will crush the grapes and ferment both the juice and the skins. This makes the wine red in color and adds tannins, which gives the wine a dry taste. White wine is made by removing the grape skins and fermenting only the juice.

Beer Ingredients

Beer is slightly more complex than wine. Beer is mostly water, about 90 percent depending on the style and brand. Barley is added to the water, which is the source of food for the yeast. Beer will typically be under 5 percent alcohol once it is finished. Beer brewers also add hops to the beer mixture to add a distinct, bitter flavor. Ale style beer has yeast that is fermented at the top of the mixture at a higher temperature while lager is fermented at the bottom of the mixture at a lower temperature.

References

• Alabev: The Ingredients of Beer
• YoBrew: Alcoholic Fermentation by Yeast Cells
• Virtual Wine: Fermentation Process