Floral foam is one of the oldest and most common cigar humidifiers. It has become a standard accessory found in most store-bought humidors. Floral foam, also known as "Oasis foam", is in fact a super-absorbent phenolic foam manufactured by the
Smithers-Oasis Company. Once immersed in water, a capillary action occurs and water rises to its surface to be released from time to time. Floral foam humidifiers are normally packaged in plastic containers with holes or slots to allow moisture to escape. To fill them, simply place the foam on a paper towel and pour in distilled water or activator solution until it overflows the surface of the foam. Then wait a few minutes for the excess to gradually drip off and the foam to absorb the rest. Then turn the container upside down to drain off any excess drip. By tapping the container on a table or shaking it over the sink, you ensure that any excess liquid is removed. This way, your cigars won't become saturated with moisture. Finally, place the container inside your
humidor and close it. Foam humidifiers should be refilled every 1-2 weeks. Always keep an eye on the humidity level in your
humidor, as well as the condition of your cigars. If the humidity level drops below 70%, or if your cigars start to dry out a little, refill your cigar humidor. Be aware that floral foam is very porous and will eventually absorb some of the molecular by-products created by your cigars as they age, notably ammonia. Over time, it will lose its ability to absorb moisture properly and will need to be replaced. This is usually done every 6 to 12 months.
Water and propylene glycol solution Many cigar collectors prefer a water-based alternative. They refill their cigar humidifiers with a propylene glycol activator solution. Propylene glycol is hygroscopic at 70% relative humidity. Behind this rather complicated way of putting things, it actually means that once the relative humidity in your humidor reaches 70%, the propylene glycol solution stops releasing moisture. On the other hand, if you use water to fill your cigar humidifier, the humidity in your humidor will experience a rapid rise in humidity followed by a rapid decline in humidity.
Propylene glycol has the advantage of releasing moisture gradually, ensuring more regular humidity levels over time. If you do use water, always prefer distilled water to tap or bottled water: the minerals they contain can clog your humidifier and prevent it from performing its function.
Disadvantages The main disadvantage of floral foam humidifiers is the high risk of mold growth. Indeed, the high levels of humidity they deliver also make them ideal breeding grounds for mold spores. Opting for a 50% propylene glycol solution will reduce the risk of over-humidity, but will not eliminate it completely. In any case, if you use floral foam, check regularly that it contains no mould. If it does, discard it immediately.