Relative humidity (RH) within a humidor is optimally held stable at any one point between 62-70%, says Carnley. Insufficient humidity can cause the wrapper leaf of a cigar to become brittle and very susceptible to damage, or even crack on its own. It can also cause the cigar to lose flavor and burn too quickly.
In contrast, excessive humidity can cause the cigar to have difficulty remaining lit, and its profile becomes muted and takes on a bitter taste. Over time, excess humidity can even cause mold growth or dormant microscopic tobacco beetle eggs to hatch.
Though this is less of a concern today than it used to be, says Cory Carnley, many manufacturers freeze cigars before or during transport to neutralize eggs that may be present.
What is a hygrometer?
A hygrometer (not to be confused with a hydrometer), says Carnley, is a gauge that measures RH. Although they are not a necessity, they provide one with important information required to more diligently care for their collection.
Which is better, analog or digital?
Beware of analog hygrometers; though they do have a classy look, they are notoriously inaccurate. Digital hygrometers are the better option, though naturally, some models are more reliable than others.
There are few hygrometers that have made a name for themselves, says Cory Carnley, but one is the Cigar Oasis Caliber 4R. While a great tool to have, this $25 hygrometer is not necessary for most enthusiasts.
Humidification Devices Fall Into One of Two Major Categories: Active & Passive
According to Carnley, active humidification devices emit moisture into the air via mechanical means, whereas passive devices emit moisture strictly via osmosis. Active devices are geared by design more toward larger spaces (large cabinet or walk-in humidors, etc.), but some companies (like Cigar Oasis) do produce smaller units suitable for desktop humidors.
All active devices are refillable and intended for long-term use. Most passive devices are as well but some, like Boveda packs, are intended to be disposable.
Active Devices
Most of these types function very similarly to passive devices, says Carnley, excluding some larger commercial units which utilize such things as in-line reverse-osmosis systems and ultrasonic technology. They have a reservoir in which distilled water would be stored. Some have a containment medium, such as floral foam.
The desired RH would be programmed by the user and the unit’s fan(s) will activate to disperse moisture throughout the humidor. The unit itself would have a hygrometer in order to properly regulate emission.
Depending on the size of the humidor for which the unit is designed, says Cory Carnley, it may have a separate wired hygrometer intended to be placed a distance from the unit itself, so that it is able to accurately gauge RH throughout, rather than merely in its direct proximity.
Types of Passive Devices:
Passive humidification devices, says Carnley, come in four basic types, including:
- Floral Foam
Floral foam devices are very common because they are included with virtually every desktop humidor. They are shells generally made of plastic with a piece of green floral foam inside intended to be soaked with distilled water or a humidor solution. These foam devices are often used by beginners or occasional cigar smokers.
Due to their unregulated emission and reputation for mold growth, says Cory Carnley, more seasoned enthusiasts avoid floral foam in favor of other devices.
- Floral Crystal Gel
Floral crystal gel devices are identical in function to the floral foam devices, except they use polymer crystal gel as the medium, which carries less of a reputation for mold. These devices are available in containers of various form factors and can be filled with either distilled water or a PG solution.
As Carnley knows, some crystal gel devices are already treated with propylene glycol, which requires them to only be filled with distilled water. It can be discerned that a product has already been treated when it says it is rated for 70% RH.
- Silica beads
Silica beads are lesser-used passive devices but are generally well-thought-of among more serious enthusiasts. The most popular and reputable brand is Heartfelt Industries. These are not to be confused with crystal gel beads (floral beads). These beads are sold in both a 65% and 70% RH rating and come in a variety of containers.
They are intended to be refilled only with distilled water; PG solution is not to be used with these.
- Two-way humidification packs
According to Cory Carnley, two-way packs are extremely popular, though the only notable brand is Boveda. Such packs offer efficient passive two-way humidification, meaning that they will emit or absorb however much moisture is necessary to reach the RH level for which they have been rated.
Boveda produces cigar humidification packs rated for 62%, 65%, 69%, and 72%. Note that 72% packs are not intended for airtight humidors, like acrylic jars, says Carnley because such a high humidity has a significant chance of eventually causing mold growth.
72% packs are acceptable for wooden humidors because their wood-on-wood seals are not airtight and their porous interiors continuously fight for the environment’s moisture.
The packs consist of a solution of distilled water, salts, and a food-grade gumming agent, encapsulated in a semi-permeable membrane and covered in tough, breathable paper. These are designed to be disposable but many consumers have taken to trying to “recharge” them through various methods, although there is debate over the efficacy of this.
Which Solutions Work Best for Cigar Humidification?
According to Cory Carnley, there are two primary solutions used in cigar humidification devices:
- Distilled water
Distilled water is used in both active and passive devices. No varieties of water other than distilled are acceptable for use. Other types increase the possibilities of developing mineral deposit clogs and mold, in both passive and active devices. According to Carnley, only distilled water is acceptable in both types of devices.
Impurities within the water may also alter the cigar flavor. Passive devices filled with nothing but distilled water will continuously emit moisture without regulation, so these are not the choice for an enthusiast who desires to create specific conditions within their humidor.
- Propylene glycol solution
Propylene glycol solution (PG solution), says Carnley, is only used in passive devices. The advantage of the solution is that the PG acts as an antifungal, helping prevent mold growth. It also acts as a hygroscopic, attempting to regulate the RH in the humidor.
Not all solutions are created equal. PG solutions are sold by many different companies under many different names, such as “activating solution” or “humidor solution”, and personal experience with these products varies wildly. Many report great success with a stable 70% RH and no issues, others that their humidity skyrocketed or that their device became clogged.
Cory Carnley: Listen to the Experts
According to Carnley, one of the largest cigar accessory manufacturers, Xikar Inc., touts their solution to be formulated in such a fashion as to allow water to evaporate at the same rate at which the PG biodegrades, averting the risk of clogging.
But even Rob Lembke, the former Vice President of Engineering and Process Excellence at Xikar, does not recommend that Xikar’s solution or any other PG solution be used in an active device. Lembke says that PG being near the system is “risky” and explains that the hygroscopy is a moot point because active devices are designed to emit moisture mechanically until the selected RH has been reached, and many units’ reservoirs are sealed from the air within the humidor until emission begins.
For use of most PG solutions with passive devices, Lembke recommends that it be used every three to four times, and distilled water be used for all others. And as Cory Carnley knows, products pre-treated with PG carry the same unreliability.
