Should I store bottles of wine upright or on their sides?

Dear Dr. Vinny,

I belong to a wine club at my golf course where I have a climate-controlled locker for storing wine bottles. My bottles are currently stored standing up, but I’ve been told they need to be laid flat. Which way is correct, and why?

—Stephen, Port St. Lucie, Fla.

Dear Stephen,

Storing wine bottles on their sides keeps the corks moist. This is important because if a cork dries out, it can shrink and let air into the bottle (and possibly let some wine leak out). That, in turn, can oxidize your wine, meaning it will prematurely age and its flavors will fade (it’s also a pain to open a bottle with a dry, crumbly cork). When a bottle is stored on its side, the part of the cork that’s on the inside of the bottle, in contact with the wine, will stay wet, which is usually enough to prevent the cork from drying out. For the part of the cork that isn’t in contact with the wine, having a cellar with around 70 percent relative humidity is a good idea.

Of course, this is specific to wines sealed with natural corks. If your wines are topped with something else—say a screwcap—it’s not necessary to store the wine on its side, but it also doesn’t hurt. You might occasionally even see wine stored upside-down, but it’s generally best to stick with horizontal storage, especially in the long term. Many cellars, lockers and other spaces for storing wines are designed for keeping bottles on their sides, so you may also find it’s more efficient to keep them horizontal.

For more tips on keeping your precious bottles in tip-top shape, check out our guide to proper wine storage!

—Dr. Vinny