Red wine ferments at a higher temperature than white wine.
During fermentation of red wine, the temperature of the must rises to between 60°F and 85°F. The winemaker usually does not want it to rise above 85°F, for at higher temperatures, the aromas and flavors of the wine may be volatilized or burned off. White wines, (except from some wines like full-bodies Chardonnays) are often fermented in temperature-controlled fermentation tanks, so they generally ferment at 50°F to 65°F. These tanks are usually double-skinned and wrapped on the outside with a jacket through which a coolant like glycol can run. Again, the goal is to preserve the wine’s aromas by fermenting at a cool temperature.