This is a tricky topic because if your cigars are too dried out there may be no hope. However, it can’t hurt to try, right? That caveat aside, here goes, but you will need to be patient as the process of restoring dry cigars can take weeks or even months:
Put the cigars in a humidor or other sealable container with a humidifier that hasn’t been re-charged lately. Let them rest in there for a few days so the cigars absorb what little humidity remains. Then, only partially fill the humidifier, letting the cigars rest again for about a week. Then fully re-charge humidifier. The idea here is to allow slow absorption of moisture, preventing the dry cigars from getting too much humidity too soon. If you shock the cigars by adding too much moisture at once they can actually burst–the last thing you want to do with really pricey cigars. This can take several weeks to more than a month. Remember, be patient.
If you have a very large humidor or cabinet-style humidor, start by placing the cigars a good distance from the humidifying device and every 5-7 days, move them a little closer to the humidifying device. This could take up to six weeks, so again, patience is key.
Before you light up, make sure the now-restored cigars have a little “spring” to them like a fresh cigars should be. Dry cigars will only burn hot and the flavor bitter tasting.