Every year around this time, we get a version of the same call: a member's cave, which had been holding a steady 85 to 90 percent humidity all fall, suddenly starts reading in the 60s. Nothing about the cave changed. What changed is that the building around it got a furnace running, and forced-air heat is one of the most efficient humidity thieves in a small production facility. Cold air simply can't hold as much moisture as warm air, so the moment you heat it, its relative humidity drops — and if your cave shares any airflow at all with the heated part of the building, that dry air finds its way in.
This matters more in early December than at almost any other point in the year, because it's exactly when a lot of members are also asking their caves to hold more inventory than usual for the holiday case. A rind that's drying out faster than planned, on wheels you're counting on for gift boxes and year-end orders, is a bad combination. The good news is that this is one of the most fixable problems in cheesemaking, once you know to look for it.
What to check first
Start with where your make room and your aging space share a wall, a door, or a duct. If your furnace vents anywhere near the cave, even indirectly, you'll likely see the humidity drop track the thermostat almost exactly — check your logs against your heating schedule and the pattern usually jumps right out. A door that gets propped open more often in winter, because staff are moving product in and out for holiday orders, is another common and often-overlooked culprit.
Once you've found the source, the fix is rarely a bigger investment than a humidifier and some weatherstripping. A standalone humidifier sized to your cave's volume, run on a hygrometer-controlled cycle rather than continuously, will usually recover a healthy range within a day or two. Sealing gaps around doors and ducts keeps that recovery from being undone every time someone opens the cave to pull holiday orders. For members running a walk-in cooler as their aging space, check the door seal specifically — those wear out faster than people expect, and a compressor working harder in winter can dry the air inside as a side effect.
The course that covers this properly
We built our cave management coursework for exactly this kind of seasonal shift, not just cave setup from scratch. It walks through the relationship between your building's heating and cooling systems and your aging environment, how to read a hygrometer against a real production schedule rather than a static target, and how to build a monitoring routine that catches drift before it shows up as cracked rind on a wheel you were planning to sell in three weeks. If you've been guessing at humidity fixes based on trial and error, the course will save you a season or two of that guessing.
For most members, the actual fix takes less time than reading this post did. What takes longer is remembering to check, especially during a month when everyone's attention is on orders rather than the room the orders are aging in. Put a reminder on your calendar to check your cave hygrometer against your heating schedule this week — before your gift boxes are the thing that tells you something changed.
The International Cheese Federation (ICF) and More Cheese are entirely fictional. This post is demonstration content created for MemberJunction. All people, organizations, events, courses, certifications, figures, and quotations in it are invented, and nothing here represents a real association, a real business, a real person, or real professional advice.