How to Season a New Humidor.
STEP ONE: Do Not Put Cigars In Your New Humidor.
Now that you have a new humidor, the first thing to do is not put cigars inside. First and foremost, you must season a new humidor before storing your beloved stogies. This is also true for an old humidor that hasn't been used in a while. The cedar inside of a humidor is part of the humidification system and acts to provide humidity (and flavor) to the cigars, along with the humidification device. If the cedar has not been seasoned, then the wood will actually rob moisture from the cigars and dry them out. This effect is the exact opposite of what you wanted when you purchased the humidor.
STEP TWO: Wipe the Inside of the Humidor With Distilled Water.
Note: Before you begin the seasoning process, make sure to read any directions that may have come with your new humidor. Always follow the manufacturer's instructions so you do not void your warranty. Absent any specific instructions from the manufacturer of the humidor, proceed as follows. To season a humidor, all you need is some distilled water, a clean unscented sponge or cloth, and some patience -- at least for a few days. Do not use tap water in place of distilled water. Start by dampening a clean sponge or cloth with distilled water, then wipe down all the cedar wood inside of the humidor, including the lid and any trays. To avoid damaging the humidor, do not overly saturate the interior wood with water. Do not spill the water inside the humidor (and then try to spread it around).
STEP THREE: Place the Sponge Inside the Humidor.
Put the wet sponge on top of a piece of cellophane (or plastic bag) and place inside the humidor. Make sure that the sponge is not overly saturated and not touching any wood.
STEP FOUR: Fill Your Humidification Device.
Fill your humidification device with either distilled water or a humidifying solution, according to the manufacturer’s instructions. Make sure that the device is not overly saturated by letting any excess water drip out (into a sink), then wipe off any drops of water on the outside of the humidification device and place the device inside the humidor.
STEP FIVE: Wait 24 Hours and Repeat.
Now comes the hard part, close the humidor for 24 hours and wait. The next day, repeat the wipe down procedure using distilled water and the sponge, but do not leave the sponge inside this time and wait another 24 hours.
STEP SIX: Check for Dampness Before Adding Cigars.
On the day after the second treatment, it should be safe to use the humidor, as long as you cannot feel any dampness on the cedar. If so, then wait one more day before storing your cigars. If you have a hygrometer inside the humidor, ignore any higher-than-normal readings during the seasoning process. However, if the humidity is lower than 72% on the day after the second treatment, then repeat the wipe down procedure for a third time (you may also need to test your hygrometer or recharge your humidification device).
Article Source: ThoughtCo