Why Isn't My Humidor Holding Humidity? Troubleshooting Low RH
A humidor not holding humidity is like a car that won't start. It is frustrating, inconvenient, and failing at the one job it was built to do. When your premium cigar collection is at stake, you cannot afford to wait. It is time to roll up your sleeves and figure out what is going wrong.
Below, we will dive into the most common reasons cigar humidors lose humidity and the specific tests you can perform to fix the issue, or determine if it's time to invest in a more reliable cigar humidor.
1. You Skipped the Seasoning Process
Seasoning your humidor is a non-negotiable rite of passage. A humidor fresh out of the box is bone dry. The untreated Spanish cedar inside will act like a sponge, quickly absorbing all the moisture from the air and your cigars. This leaves your sticks dry and brittle.
If you never seasoned your box, or if it has been months since your last deep-fill, this is likely your culprit. Fortunately, this is an easy fix. Check out our Humidor Seasoning Guide for step-by-step instructions. Season it properly once, and you will restore the wood's ability to buffer moisture.
2. Testing for a Leaky Seal
If your humidor is not sealing properly, you might as well be storing your cigars in a cardboard box. Even the smallest gap can let moisture escape faster than your humidifier can replace it. To diagnose a bad seal, use these three expert tests:
The Dollar Bill Test
Open your humidor and place a dollar bill halfway across the front edge of the box. Close the lid and try to pull the bill out. If it slides out with zero resistance, your seal is weak. Repeat this on the sides and back of the box to find the exact location of the leak.
The Whoosh Test
Lift the lid about three inches and let it drop. A high-quality humidor should make a soft "whoosh" sound as air is displaced. If the lid slams shut with a loud "clack," there is no air resistance, which means your seal is failing.
The Flashlight Test
Place a bright LED flashlight inside your empty humidor and turn it on. Take the box into a completely dark room and close the lid. If you see light escaping from the edges, you have found your gap. This is especially common with a glass top humidor where the seal between the glass and the wood may have dried out.
Pro Tip: If your humidity continues to fluctuate despite proper maintenance, the issue is often a compromised seal. Investing in professional-grade Desktop Humidors with reinforced hardware and precision-seated lids is the only permanent way to ensure long-term RH stability.
3. An Inaccurate Hygrometer
Sometimes, the problem is not the humidor; it is the sensor. If your hygrometer is giving you bad readings, you are making adjustments based on false data. Analog hygrometers are notorious for losing accuracy over time, often reading 5 percent to 10 percent lower than the actual humidity.
If you have never performed a salt test or used a calibration kit, your device is likely out of spec. For a step-by-step guide on how to fix this, check out our article on Calibrating a Hygrometer.
4. Humidifier Maintenance and Propylene Glycol
Your humidifier is the engine of your box. If you are using a traditional sponge or floral foam humidifier, you must use a Propylene Glycol (PG) solution instead of just distilled water. PG solution is a two-way regulator; it prevents humidity from spiking above 70 percent and keeps water from evaporating too quickly.
If you are using Boveda packs, check their texture. When they feel stiff or crunchy, they are exhausted. If your packs are drying out in less than a month, it is a sign that your humidor is either unseasoned or leaking air.
5. External Environment and Placement
External conditions such as heat and drafts can overpower even the most well-constructed desktop humidor.
- Heating Vents: Placing your box near a radiator or space heater will dry out the surrounding air and bake the wood.
- Direct Sunlight: Sunlight causes internal temperature spikes. This creates a "greenhouse effect" that forces moisture out of the wood and can even lead to cigar mold.
- Airflow: Keep your humidor in a cool, dark place with minimal temperature changes. A closet or an interior shelf is often the safest spot.
Final Thoughts
A humidor that isn't holding humidity is a problem you can solve. By checking your seasoning, testing your seal with a dollar bill, and ensuring your cigar humidity levels are backed by an accurate hygrometer, you can restore balance to your collection.
