Having a correctly calibrated hygrometer can be the difference between a delightful afternoon smoke and an overly harsh or even unpleasant smoking experience. If your hygrometer isn’t accurate, you could ruin your cigars without knowing it. Luckily, calibrating the hygrometer is simple and there are two easy tests you can easily do yourself.

The Salt Test: Our recommended calibration method

  1. Gather the materials for the test:
    - small ziplock bag
    - bottle cap from a soft-drink bottle
    - table salt
    - your hygrometer (digital or analog)
  2. Now it’s time for the test. Fill the bottle cap 3/4 the way up with salt.
  3. Add enough water so that the salt is completely wet, but no water is floating on top. If you’ve added too much water, simply absorb the excess by placing a paper towel over the top of the bottle cap.
  4. Once you’ve created the salt/water mix without any excess water, place the bottle cap and the hygrometer carefully into the Ziplock bag.
  5. After four hours, check the reading on your hygrometer. It should read 75% (plus or minus 3%). If the reading is incorrect, follow the directions on your hygrometer to adjust the reading to 75%.

The Wet Towel Method: it’s not quite as reliable but will work in a pinch

  1. Wet a towel completely but not so wet that it’s dripping.
  2. Wrap the towel completely around your hygrometer.
  3. After 30 minutes, check your hygrometer reading. It should be 98% or more.
  4. If the reading is 98% or more, your hygrometer is calibrated and you can start using it for your humidor.
  5. If the reading is not 98% or more, turn the screw on the back of the hygrometer until it reads 98%.

You’ve done it! You’ve calibrated your hygrometer and it’s ready to use with your humidor.