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Fix a cigar humidor that will not hold humidity

We'll calibrate the hygrometer, check the seal, confirm seasoning, then isolate the cause—humidification device, placement, or wood—or tell you when to replace the humidor.

Troubleshooting · Home appliances
15 min–2 weeks
What you'll need
  • Distilled water (for seasoning and humidification devices)
  • Salt (for hygrometer calibration)
  • Small plastic bag (for salt test)
  • Replacement Boveda pack or gel (if the humidification device is dry)
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Steps

Goal: Confirm the symptom, calibrate the hygrometer, check the seal, then isolate the cause—seasoning, humidification device, or placement.

  • Check the hygrometer reading. If it stays below target (e.g. 65–72% RH) or drops after you add moisture, the humidor is not holding humidity.
  • Good: The reading is low or drops over time—proceed to Calibrate hygrometer.
  • Bad: The reading is stable and at target—no problem. Run the salt test if you are unsure.

Calibrate hygrometer

Goal: Confirm the hygrometer is accurate before assuming the humidor is at fault.

  • Use the salt test: put a teaspoon of salt in a bottle cap, add a few drops of water to make a slurry (not dissolved), seal the hygrometer and cap in a plastic bag for 8–12 hours.
  • At 75°F the reading should be 75% RH. If it reads high or low, note the offset or adjust the hygrometer if it has a calibration screw.
  • Good: The hygrometer is calibrated. Proceed to Check seal.
  • Bad: The hygrometer is faulty—replace it or use the offset when reading.

Check seal

Goal: Rule out a poor seal—the most common cause of humidity loss.

  • Close the lid on a dollar bill or sheet of paper at several points around the edge. A good seal holds the paper firmly; a poor seal lets it slide out with little resistance.
  • Check all four sides and corners. Wipe the lid edge and lip with a dry, soft cloth. Confirm hinges are tight and the lid sits flush.
  • Good: The seal holds the paper firmly. Proceed to Seasoning path.
  • Bad: The paper slides out easily—clean the seal and hinges. If the lid is warped or hinges are broken, replace the humidor.

Seasoning path

Goal: Confirm the wood has been seasoned; new or dried-out wood absorbs moisture before RH stabilizes.

  • New humidors and those left empty for months need seasoning. Wipe the interior with a damp cloth (distilled water), or place a small bowl of distilled water inside and close the lid for 1–2 weeks.
  • When the hygrometer holds steady, remove the bowl and add cigars. If the humidor was left open or empty for a long time, re-season.
  • Good: The wood is seasoned. Proceed to Check humidification device.
  • Bad: The wood was not seasoned—season for 1–2 weeks, then retest.

Check humidification device

Goal: Confirm the humidification device is moist and sized for the humidor.

  • Inspect the humidification device. Boveda packs feel firm when good; when dry they become stiff and brittle. Gel and crystal units need distilled water refills.
  • Confirm the device matches the humidor size (e.g. one 60g Boveda per 25 cigars). For large humidors, add a second device or use a larger unit.
  • Good: The device is moist and sized correctly. Check placement.
  • Bad: Replace dry Boveda packs or refill gel/crystal units. Add a second device if undersized.

Check placement

Goal: Rule out heat, vents, and sunlight—they increase evaporation.

  • Move the humidor away from windows, radiators, and HVAC vents. A stable room temperature (65–72°F) helps.
  • Good: The humidor is in a cool, stable spot. If humidity still drops after all steps, replace the humidor.
  • Bad: The humidor is near heat or drafts—move it and retest.

When to get help

Replace the humidor or call a pro if:

  • The seal cannot be fixed—warped lid, cracked hinges, or visible gaps that persist after cleaning.
  • You have calibrated the hygrometer, seasoned the wood, used a fresh humidification device, and fixed placement—and humidity still drops.

A defective humidor cannot hold humidity. Call a cigar specialty retailer for replacement advice or replace it with a new one.

Verification

  • The hygrometer reads at target RH (e.g. 65–72%) and holds steady for days.
  • The seal passes the dollar-bill test—paper has resistance when pulled.
  • The humidification device is moist (Boveda firm, gel/crystal refilled).
  • The humidor is away from heat, vents, and direct sunlight.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. Calibrate hygrometer Use the salt test to confirm the hygrometer reads correctly.
  2. Check seal Dollar-bill or paper test around the lid; poor seal is the most common cause.
  3. Seasoning New or dried-out wood needs 1–2 weeks of seasoning before RH stabilizes.
  4. Humidification device Replace dry Boveda packs; refill gel or crystal units with distilled water.
  5. Placement and capacity Move away from heat and vents; add or upgrade the humidification device if undersized.
  6. Call a pro or replace Warped lid, broken seal, or persistent humidity loss—call a cigar specialty retailer for replacement advice or replace the humidor.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • Hygrometer reading before and after calibration
  • Whether the seal passes the dollar-bill test
  • Whether the humidor has been seasoned
  • Type and condition of humidification device
  • Placement (near heat, vent, or sun)
  • Steps already tried

Does the hygrometer read low or does humidity drop over time?

Check the hygrometer reading. If it stays below target (e.g. 65–72% RH) or drops after you add moisture, the humidor is not holding humidity.

Check the hygrometer reading. Good: reading is low or drops over time—humidity-holding fault. Bad: reading is stable and at target—no problem; check calibration if unsure.

Yes No

You can change your answer later.

Humidor holds humidity

If the hygrometer reads at target and holds steady, the humidor is working. If you are unsure, run the salt test to calibrate.

Done

Has the hygrometer been calibrated?

A faulty hygrometer reading is common. Use the salt test before assuming the humidor is the problem.

Use the salt test: salt + a few drops of water in a cap, seal with the hygrometer in a bag for 8–12 hours. At 75°F it should read 75% RH. Not calibrated: calibrate first. Calibrated and still low: proceed to seal check.

Yes No

You can change your answer later.

Calibrate hygrometer and retest

Run the salt test. Note the offset or adjust the hygrometer if it has a calibration screw. After calibration, check the humidor again. If the reading is still low, proceed to Check seal.

Done

Does the seal pass the dollar-bill test?

Close the lid on a dollar bill or paper at several points. A good seal holds the paper firmly.

Close the lid on a dollar bill or paper around the edge. Poor seal: paper slides out easily—clean the seal, check hinges, or replace the humidor if warped. Good seal: paper has resistance—proceed to seasoning.

Yes No

You can change your answer later.

Fix seal or replace humidor

Wipe the seal and hinge with a dry cloth. Check that the lid sits flush. If the lid is warped or hinges are broken, replace the humidor. If cleaning fixes it, retest with the dollar-bill test.

Done

Has the humidor been seasoned?

New or dried-out wood absorbs moisture before RH stabilizes. Seasoning takes 1–2 weeks.

Check if the humidor is new or was left empty for months. Seasoning means wetting the interior wood for 1–2 weeks. Not seasoned: season the humidor. Seasoned: proceed to humidification device.

Yes No

You can change your answer later.

Season the humidor

Wipe the interior with a damp cloth (distilled water) or place a small bowl of distilled water inside for 1–2 weeks. When the hygrometer holds steady, remove the bowl and add cigars. Re-season if the wood dried out from being left open.

Done

Is the humidification device moist and sized correctly?

Boveda packs dry out; gel and crystal units need refills. The device must match the humidor size.

Check the humidification device. Boveda: firm when good, stiff and brittle when dry. Gel/crystal: refill with distilled water. Confirm size (e.g. one 60g Boveda per 25 cigars). Dry or undersized: replace or add devices. Good: check placement.

Yes No

You can change your answer later.

Replace or add humidification device

Replace dry Boveda packs with fresh ones. Refill gel or crystal units with distilled water. Add a second device if the humidor is large. Retest after a few days.

Done

Is the humidor away from heat, vents, and sun?

Heat and drafts increase evaporation and make humidity harder to hold.

Move the humidor away from windows, radiators, and HVAC vents. A stable room (65–72°F) helps. Bad placement: move it. Good placement: if humidity still drops, the humidor may be defective—replace it.

Yes No

You can change your answer later.

Move humidor and retest

Move the humidor to a cool, stable spot away from drafts and heat. Wait a few days and check the hygrometer. If it holds, the placement was the cause.

Done

Replace the humidor

If you have calibrated the hygrometer, checked the seal, seasoned the wood, used a fresh humidification device, and fixed placement—and humidity still drops—the humidor is likely defective. Replace it.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would a cigar humidor not hold humidity?
Common causes: a poor seal (lid does not close tightly), an uncalibrated or faulty hygrometer, wood that needs seasoning or has dried out, an empty or undersized humidification device, or placement near heat or vents. Calibrate the hygrometer first, then check the seal.
How do I calibrate a hygrometer?
Use the salt test: put a teaspoon of salt in a bottle cap, add a few drops of water to make a slurry (not dissolved), seal the hygrometer and cap in a bag for 8–12 hours. At 75°F the reading should be 75% RH. Adjust the hygrometer or note the offset.
When should I replace a cigar humidor?
Replace the humidor if the seal cannot be fixed—warped lid, cracked hinges, or visible gaps that persist after cleaning. If humidity still drops after calibrating the hygrometer, seasoning, and using a fresh humidification device, the box may be defective.

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