Xikar 8oz Propylene Glycol - Solution for HumidorXIKAR knows best. When it comes down to it it's this that makes all of the difference. Using only distilled water will let the humidity in your humidor vary anywhere between 35% and 95% depending on the outside conditions so you're constantly checking your humidor. Charge your humidor with XIKAR's proprietary Propylene Glycol liquid and the carefully formulated mixture will maintain the relative humidity (RH) at a steady 70% meaning you don't have to