When talking about 70% RH, unless you know the temperature at which the humidity is being measured, you have no idea of the condition of your cigars. For example, the hygrometer could be reading 90% RH, but the cigars could be desert-dry! Conversely, they could be swamp-soggy, even at 50% RH. It all depends upon the temperature at which the humidity is measured. Relative humidity is the amount of water vapor the air is holding, expressed as a percentage of( or relative to) the maximum amount it could hold at that temperature. Thus, 50% RH means the air is holding half the vapor it could hold at that temperature, if it were staurated and getting ready to rain. Cigars, being native to third world countries, don't have the educational background to comprehend RH. All they know is how much actual water vapor they feel on their crinkle little skins. This actual amount of water vapor in the air is called absolute humidity(AH). It isn't expressed as a percentage; it's the actual weight of all the water vapor molecules (in thousandths of a gram) inside a one-liter container. The the cahart accompanying this article, our optimal humidor condition, 70%RH at 70 degrees F, corresponds to an AH level which is the magic number-- it relates to the ideal amount of water vapor molecules carressing your darlings. Though not univerally recognized, some of the biggest name sin the tobacco industry -- Habanos SA, for example -- recommend 70/70. Now, if the temperature drops to 65 degrees F, notice that, although the numbe rof water molecules(the AH) hasn't changed, the RH has climbed to 83%. Are the cigarsgetting overly moisturized because of the increased RH? No, they are still be bathed in the same absolute humidity-- the same amount of moisture that they felt at 70 degrees. Why did the RH go up then, then, if the AH stayed constant and the temperature dropped? Because, the percentage of vapor it's holding, compared to what it can hold, has increased -- it's approaching saturation. The air can't hold as much water vapor as it could at a higher temperature. And at 60 degrees F, uh, oh! The air can't hold enough moisture to give your cigars what they needed at 70 dgrees to give you 70% RH. So, if the temperature is 65 degrees and you want to maintain the absolute humidity that is equivalant to 70% RH at 70 degrees, your hygrometer must be rading 83% RH, or your cigars are too dry. It all works in the reverse at temperatures above 70 degrees. As temperature increases, RH does downwith constant AH, as you can see. Keep in mind, then, knowing the relative humidity is meaningless, unless you know the temperature.
DETERMINING CORRECT HUMIDITY OF CIGARS
The standard for cigar storage os 70% RH, but only at 70 degrees F. At temperatures below 70 dgrees, RH readings must be greater than 70% to give the same humidification as 70%/70 degrees. At temperatures above 70 degrees, RH readings must be less than 70% for proper results.
|
TEMPERATURE
(FAHRENHEIT)
|
R.H. REQ'D TO EQUAL 70% at &) F |
| 80 |
49% |
| 79 |
52% |
| 78 |
53% |
| 77 |
55% |
| 76 |
57% |
| 75 |
59% |
| 74 |
61% |
| 73 |
63% |
| 72 |
65% |
| 71 |
68% |
| 70 |
70% |
| 69 |
72% |
| 68 |
75% |
| 67 |
78% |
| 66 |
80% |
| 65 |
83% |
| 64 |
86% |
| 63 |
89% |
| 62 |
92% |
| 61 |
96% |
| 60 |
Not Possible |