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.
Sometimes humidors come equipped with a thermometer, but usually that isn't necessary. Temperature and humidity tolerances. Cigars like to kept at 70 degrees Fahrenheit (21.1 degrees Celsius) and 70% humidity. This can be in a range of 65% to 75% depending on whether you like your cigars a little dry or a little wet. Some say Cuban cigars ought to be kept at 65% to allow them to smoke better.