When yeast ferments grape juice, fermentation temperature is an important factor for winemakers to consider and monitor. The fermentation temperature of red wine is kept between 70 and 85 degrees Fahrenheit, and the fermentation temperature of white wine is kept between 45 and 60 degrees Fahrenheit.

Fermented wine should be kept in a safe temperature range. This can be different from the production of red wine and white wine, but it can also be controlled according to the winemaker's expected results. The fermentation temperature must be monitored and kept in a safe range until the grape fermentation is completed.

Red wine should be kept between 70 and 85 degrees Fahrenheit. This temperature range allows the maximum required color and tannin to be extracted from grape skins. Higher temperature will destroy wine, turn it into vinegar, and even "cook" wine, resulting in bad aroma and flavor, such as cooked/burnt fruits and sugar.

White wine should be kept between 45 and 60 degrees Fahrenheit. The characteristics of white varieties are more subtle, and the lower temperature helps to preserve the faint fruity and volatile aroma, otherwise these aromas may be "cooked". Because of the low fermentation temperature, this process takes a long time. Red wine fermentation can end in 2 to 2.5 weeks, while white wine fermentation may take several months.