“To decant or not to decant,” that is the question. But it’s not a complicated one if you follow a few simple tips.

First, if the wine is likely to “throw a deposit,” you should decant. Deposits form as substances naturally precipitate out of the wine and fall to the bottom of the bottle.

Although harmless, these gritty substances can prove unpleasant should they enter your glass. Older wines and unfiltered wines often contain such deposits, and the bigger, deeper red wines, such as Cabernet Sauvignon, Merlot and Syrah are more likely to have a deposit than are lighter reds like Beaujolais. If you wonder whether a wine is unfiltered, check its label or its winery’s web site.

Next, consider whether a little air will improve the wine’s flavor. Decanting allows wines—mostly red—to aerate before serving, softening astringent tannins and integrating flavors before entering your glass. Absent decanting, many otherwise excellent wines may prove disappointing simply because they need to “open” and take in a little air. Wines that benefit most from air exposure are those featuring high tannins—usually dark and full-bodied selections such as Bordeaux blends, Cabernet Sauvignon, Syrah/Shiraz, Cabernet Franc, Merlot, Malbec and other similarly intense reds.

Before you decant, rest the wine for a day or two in an upright position to allow sediment to settle at the bottom. Then find a decanter or container that allows a wide surface of the wine to come in contact with air. After opening the wine, gently pour it into the container, working to keep the sediment below the neck of the bottle. You may need to leave a little bit of wine in the bottle to avoid pouring sediment into the decanter.

Decanting time varies from 20 minutes to several hours for really concentrated and intense red wines, such as a premium Bordeaux or some intensely tannic Shiraz wines from Australia. Sampling the wine as decanting continues may be your best guide, which is particularly important when decanting older wines. Really old wines—those with a decade or more of bottle age—may quickly degrade and lose flavor after even a few minutes in some cases. For these wines, gently decant to remove any deposits, but then follow with careful monitoring to ensure the wine is consumed in its best possible condition. Some really old wines you may want drink right away.

When your wine is ready, it’s time to sit back and enjoy!