When you release the liquid carbon dioxide from the tank, the expansion of the liquid and the high-speed evaporation of carbon dioxide gas cools the remainder of the liquid down to the freezing point, where it turns directly into a solid.
Quick Answer. Cigars stay fresh without a humidor for up to a month when kept in their original wrapper. Cigars kept in a humidor can last for years in a properly controlled environment. A humidor keeps cigars from drying out and the oils from evaporating. Keep Learning.
The first thing to know is that cigars should stay in a humidor (the first syllable rhymes with you, as in the word humid) until they're ready to be smoked. When necessary, you can get away with keeping properly humidified cigars in a sealed plastic bag with a small, damp paper towel for a day or so.