Without being too fussy about exact degrees, it is easy to follow several easy tips to best enjoy a good bottle of wine. A good general rule is that cold deadens aromas.

Cold hardens white wines, increasing the sensation of acidity. The same applies to reds.
Cold increases wines rough, raspy characteristics, such as red wines astringent tannins and dryness.
Heat hides white wines’ delicate, subtle aromas by increasing perception of their alcohol content.
Heat accentuates the alcohol component of red wines, masks their finesse and ruins their balance.
Heat intensifies astringency.

Keeping these few factual principles in mind, you can see why red wines should be consumed at a higher temperature than whites, and that full-bodied, tannic reds should be served warmer than light, lively reds.

Here are several additional recommendations. During the summer months, do not hesitate to chill reds slightly, especially in restaurants where they may be stored in overly warm conditions. Red wines lose their complexity at temperatures higher than 18°C (64°F) and modern day houses (without wine cellars) can easily reach 25°C (77°F). The best method is a bucket of cold water with ice, as the cold rapidly passes through the glass bottle to chill the wine. It is better to serve the wine a bit too cold, as it will not take long to warm in the glass. To chill a white wine, the best strategy is to gradually cool it in the refrigerator. See the illustration (opposite) for details.