Humidor hygrometers can be calibrated using special calibration kits, the salt test or even using a wet towel. Learn one of these methods to ensure your cigars are safe in the right humidity.
Finally have a good humidor for your cigars? Then it is time you learn how to handle the humidity inside the box.
This isn’t the same as seasoning a cigar box – that’s a whole other maintenance story. Calibrating a hygrometer helps you accurately monitor the conditions inside the humidor so that you’re not facing any surprises when you nip at your cigar.
There are several ways to get it right and there are critics for each method. We explain each option so that you can decide for yourself which way you prefer to calibrate your hygrometer.
What Is a Hygrometer?
A hygrometer is similar to a thermometer. The only difference is that it measures humidity instead of temperature.
Many cigar humidors, or at least the higher quality kind, feature a hygrometer because humidity is an essential factor in keeping cigars fresh. The best humidors have both a hygrometer and a thermometer so that you can keep the interior at the sweet spot: 70% humidity, 70°F
Analog vs Digital Hygrometers
You can find both analog and digital hygrometers on humidors. Which one is better depends on whether you prioritize accuracy or control. In theory, both hygrometer types are accurate but the analog versions do need regular tuning to remain reliable.
If you suspect that an analog hygrometer is not reading the humidity right, it is often a simple fix. Some digital versions are also adjustable but they often have internal mechanics that you simply just have to trust that they work.
Can You Calibrate a Digital Hygrometer
With most products, the digital version is more accurate than the analog version. We assume that they have been carefully calibrated in the factory so that they will provide precise readings by the time we use them.
However, nothing is perfect. Keep in mind a small margin of error with digital hygrometers.
You cannot calibrate a digital hygrometer yourself but you can check how what the margin or error is. The best way to do this is with the salt test which we’ll explain later on.
Should You Calibrate an Analog Hygrometer
Analog hygrometers are like pianos. They can be incredible for a very long time but if you want the same constant experience, it needs regular tuning.
The advantage of an analog hygrometer is that adjusting them is easily done. Just a few turns and taps and it will read as it should.
The salt test that we recommended for the digital hygrometer works on analogs, too. Other calibration options include calibration kits and the wet towel trick.
How to Calibrate a Hygrometer on Humidors
Each of these methods are commonly used among humidor owners but none are foolproof. Still, these calibration methods have helped cigar lovers keep their stash fresh for a very long time so when done correctly, they will do the same for you.
Method 1: How to Calibrate with Hygrometer Salt Test
This is the most commonly used method but some will tell you that it isn’t the most accurate. But since it is inexpensive and only requires basic household items, it is perfect in a pinch.
Step 1: Put 2 teaspoons of table salt (sodium chloride) in the small cup or bottle cap.
Step 2: Add 2-3 drops of distilled water to the salt.
Step 3: Mix together to create a sludge. If necessary, add more water but only enough to dissolve the salt. The mixture should not be too wet.
Step 4: Place the container with salt inside the ziplock bag, without the mixture spilling.
Step 5: Place the hygrometer inside the ziplock bag, too.
Step 6: Close the ziplock bag and leave in a shaded spot on a flat surface where it won’t get knocked over.
Step 7: Let sit for 12 – 24 hours.
Step 8: At the end of the above waiting period, the hygrometer should read 75% humidity. If it doesn’t, adjust accordingly.
Method 2: How to Calibrate a Hygrometer with Boveda Packs
Boveda packs are small sachets that create specific relative humidity within a container. They are a dream come true for cigar aficionados.
Step 1: Open the Boveda calibration kit pack. It should include 1 sachet for 75% humidity and one sachet for 32% humidity. This is to test the hygrometer’s accuracy at both low and high humidity levels.
Step 2: Place the 75% RH sachet inside the humidor and leave for 24 hours.
Step 3: Check the hygrometer reading and adjust to 75% if it is off.
Step 4: Remove the 75% RH packet and replace it with the 32% RH sachet.
Step 5: Keep the humidor closed for 24 hours.
Step 6: Check the hygrometer again and adjust accordingly if it doesn’t read 32% humidity.
Step 7: Remove the 32% sachet and replace with a boveda pack that is suitable for your type of humidor.
Step 8: Wait 24 hours before placing your cigars inside the humidor.
Method 3: How to Calibrate a Hygrometer with a Wet Towel
The wet towel method is the fastest method for calibrating a hygrometer but it is also the most unreliable option. Attempt at your own risk.
Step 1: Remove the hygrometer from the humidor.
Step 2: Wet the clean towel. It should be soaked through but not dripping wet.
Step 3: Wrap the wet towel around the hygrometer for 45 minutes.
Step 4: Quickly read the hygrometer (in under 5 seconds).
Step 5: The hygrometer should be at 98% or higher. Adjust if it is not.
How Do I Know If My Hygrometer is Accurate?
This is perhaps the most important question to answer for the proud owner of a humidor. Any of the above calibration tests should tell you how precise your hygrometer readings are.
If you need to know instantly, try the wet towel method. If you can wait, just place a boveda pack inside the humidor. You will know that the hygrometer is inaccurate if it never reaches the mentioned humidity on the sachet.
Frequently Asked Questions:
How long does it take for a hygrometer to get an accurate reading?
Wait for at least 12 hours before taking a reading on a hygrometer but the most accurate readings are at 24 hours. Often when calibrating, the internal environment needs time to adjust.
How do I know if my hygrometer is working?
The wet towel test is that quickest way of knowing whether your hygrometer works. After being wrapped in a wet towel for 30-45 minutes, the hygrometer should read a minimum of 98%.
How Do I Make My Hygrometer More Accurate?
Hygrometers in humidors need regular calibration, every 3 months or so. Use the boveda calibration kit, the salt test or wet towel method to check the accuracy and adjust the hygrometer accordingly.
You need a good working hygrometer to have a good working cigar humidor. Make sure this small piece of hardware is properly calibrated to keep your cigars fresher for longer.
Although there is no single method that eliminates all margins of error, any are better than none. Many cigar lovers will recommend the boveda calibration kit and their humidity packs for long-term effect. However, the salt test and wet towel test will also give you good insight into the humidor’s accuracy.
Whichever method you choose, remember to take the readings at the right time; 24 hours for the boveda packs and salt test, 30-45 minutes for the wet towel test.
Try out these calibration methods and see how much better your cigars will taste.