When serving wine, most Americans pour refrigerator- cold whites and room-temp reds. But these defaults are based on faulty assumptions that rarely do the wines any favors.

Served straight from a 40°F refrigerator, a white wine’s aroma is diminished and its sugars and acidity are dulled. And even the most muscular red served at room temperature—68°F and above—will lack vivacity and charm.

Most wines mature gracefully at cellar temperature—48°F to 55°F. This same range is close to ideal for consuming many white wines: warm enough to display its true aromatic profile, acidity and sweetness, but cool enough to refresh. And with the exception of tannin-rich double-wides, reds show best when served in the low 60s.

But while we may want wine to put its best foot forward, few of us want to fuss over exact temperatures. So it’s helpful to think about temperature windows rather than numbers on a thermometer. The simplest way to gauge the Goldilockian mean for whites and light, delicate reds (think Beaujolais and Loire Valley reds) is by holding the barrel of the bottle in your hand. If it reminds you of a glass of water from a cold tap, you’re good. For heavier, richer reds, add a few degrees.

If your wine feels warm, there are a few easy ways to chill a bottle quickly. Nothing beats a brief stint in the freezer, which will do no harm (30 minutes generally suffice). Next quickest, a bucket with a slurry of ice and water. After that, straight ice. Forget the refrigerator, which takes hours. Even a few minutes in an ice bucket brings an overheated wine back to life.

And by the way, never be reluctant in a restaurant to put your hand on the bottle and, sensing something approaching body temperature, insist that it be iced down. Even—especially!—if it’s red.

And to warm a too-cool wine, a few minutes in tepid—not hot—water works. As wine passes from cold to cool to warm, then too warm, at some point it will pass through a sweet spot. Take note of that ideal temperature. It will help you handle the wine next time.