Chapter 6

Wine Fermentation

Wine Fermentation Temperatures

Temperature is one of the most influential factors affecting fermentation. The temperature of fermenting must affect the rate of fermentation and yeast viability, as well as the composition of volatile aroma compounds, and the extraction of anthocyanins and tannins into the wine. The temperature has a considerable influence on the fermentation rate. Cool temperatures dramatically slow the fermentation rate, and may cause its premature termination. Excessively high temperatures may induce a stuck fermentation, by disrupting enzyme and membrane function.

Red and White Wines

Red wines traditionally require higher temperature fermentation between 20 and 30 degrees C (68-86°F). Such temperatures favor not only anthocyanin but also tannin extraction. Both groups of compounds dominate the characteristics of young red wines. Color extraction is particularly important for varieties with unique anthocyanin profiles (e.g., Pinot Noir) or minimal tannin concentrations (e.g., Concord, Chambourcin, Noiret, Chancellor) that struggle to develop color (Reynolds et al., 2001).

Temperature Extremes

Yeasts are sensitive to extremes in temperature and temperature shocks. Swings in temperature greater than 5 degrees C (9°F) should be avoided. Temperature extremes also impact many of the other factors affecting fermentation efficiency listed above, e.g., nutrient requirements of yeast, ethanol toxicity, and the production of toxins.

Managing Fermentation Temperature

Heat production during fermentation can be managed with the usage of external temperature control. This typically involves controlling tank or cellar temperature to keep the wine at a relatively lower temperature than it would reach naturally.


The daily monitoring of tank temperature during fermentation is indispensable, but this measurement must be taken properly, especially with red wines. With red wines the tank temperature is never homogenous with temperature stratifications existing within the fermentation tank.


Another way to implement temperature control is through the use of controlled cellar temperatures but this method is much less efficient because of the low heat capacity of air. A traditional cellar temperature is about 15 degrees C (55°F), but 10 to 16 degrees C (50-60°F) are acceptable cellar temperatures.

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