Every fall we hear the same question from members with a cave attached to a heated building: why does the rind suddenly go tacky, or start cracking, the same week the furnace switches on for good? The honest answer is that most caves are humidity-stable right up until the building around them starts fighting the cold, and then the air a wheel sits in can shift five or ten points of relative humidity in a single week without anyone touching a dial.
This is the exact problem our Humidity & Airflow Control course was built to walk through, and December is when the enrollment usually climbs, for good reason. The course does not try to make you an HVAC engineer. It teaches you to read a cave the way you'd read a make sheet: what a sling psychrometer tells you that a cheap digital hygrometer won't, where dead air pockets tend to form near a compressor unit, and why a wheel on the bottom shelf near the door behaves differently than one at eye level in the back. If you have ever pulled two wheels from the same batch and found one rind perfect and the other chalky, the difference is very often shelf position, not the make.
Why this year's furnace season is different
This has been a strange year for cave planning generally. With in-person event traffic down sharply and course enrollment running well above a typical year, a lot of members have used the slower wholesale months to finally build out aging space they'd been putting off, and that means more first-winter caves than we usually see going into December. A brand-new cave has no thermal history yet — the walls haven't settled into a rhythm, and neither has whoever's watching them. If this is your first winter in a new room, expect to check it more often than the manual says you should, at least for the next six weeks.
There's also more inventory sitting in aging rooms right now than is typical for this point in the year. Wholesale channels have been uneven since spring, and a number of members told us on recent calls that they're holding wheels longer, betting on the holiday case rather than moving product early. Cheese prices have firmed up heading into the holidays, which makes that bet look reasonable, but it also means more wheels per cubic foot competing for the same airflow — and a crowded cave loses humidity control faster than an empty one.
For most cheeses, the target still sits somewhere around 80 to 95 percent relative humidity, with harder natural-rind styles wanting the drier end of that range and washed-rind or bloomy wheels wanting the wetter end. What changes in winter isn't the target. It's how fast a heated building pulls a cave away from it, and how much water you need to add back just to hold steady, let alone recover from a bad week.
The three things the course actually checks
The curriculum boils down to three habits, and they're worth adopting even if you never take the class:
- Log twice a day during a heating-season transition, not once. The swing between a furnace cycling on and off can be sharper than a daily reading will ever catch.
- Move air, don't just humidify it. Standing humid air breeds the wrong molds as readily as dry air cracks rinds. A small fan pointed away from the cheese, not at it, does more good than another gallon of water on the floor.
- Write down what you changed and when. The apprentices who go through this course fastest are the ones who already keep a maintenance log next to their make sheet, so a rind problem in February can be traced back to a specific December fix.
None of this replaces a working hygrometer, and none of it is a substitute for your own food-safety plan if a mold shows up that you don't recognize. It's simply the difference between guessing at a fix and knowing which lever you pulled.
If you're heading into your first winter with a new aging room, or you've just noticed this week that something in the cave has changed, the Humidity & Airflow Control course is worth a look before the next cold snap, not after the next bad rind. Reach out to the Education Committee if you want to know which cohort still has room this cycle.
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.