Thanks to Cigar Aficionado for this tip.

Q: There’s plenty of spring cleaning to do around the house, but what about inside my humidor? Should that get a good cleaning as well?

A: Yes, but humidor maintenance should be done regularly.

Keeping your humidor in top condition should be a year-round endeavor, but a thorough spring cleaning won’t hurt. This may include emptying your humidor of its cigars and cleaning out any loose bits of tobacco that may have collected in the bottom. And when we say clean, we mean use a damp cloth: Never introduce soap or any cleaning solution to your humidor, unless you want your puros to taste like Palmolive.

While you’re housekeeping, check for evidence of cigar beetles, blemishes or mold — as opposed to plume which is a sign of aging — and rotate your smokes to ensure they’re receiving equal amounts of humidity. Also change the battery in your digital hygrometer and recharge your humidifying element with a 50/50 mix of propylene glycol. If it’s very old, you may want to even replace the element. And remember: These are things that you should do on a regular basis, not just at the onset of spring.

SOURCE: cigaraficionado.com