This is how I converted a small refrigerator into a temperature and humidity-controlled "cave" for aging cheese.

While traveling in Spain, I fell in love with aged Manchego cheese: the older the better. I can easily find Imported 1-year old Manchego in the US, but it just isn't what I remember -- either the farms willing to do export aren't as good, the cheese hasn't been aged long enough, or maybe the context is all wrong and one can only enjoy Manchego in the dry winds of La Mancha. Northern California has a number of artisan cheese makers, but doesn't have a strong cheese-aging tradition. Most cheese here is measured in months, not years like in Spain. So, I decided to try aging some locally produced cheese myself.

Step 1: Plan the Cave's Construction

Donna Pacheco of Achadinha Cheese Company told me that she ages her cheese at 55°F and 80% relative humidity. That's about the same conditions you would find in a natural cave, perfect for aging cheese. (See the last step for details on the cheese I'm aging.)

The crawl space under my house is pretty cool most of the year, and I even measured the temperature of the ground a few inches below the surface at 59°F. However, there are vents to the outside, so the humidity is the same as ambient, and it rarely gets as high as 80%. I briefly considered converting a pantry with an exterior wall into a temperature-controlled cave using a window air conditioner and CoolBot controller -- but you know things are getting out of hand when you consider cutting holes in the wall for cheese you haven't yet tasted. In the end, I decided to follow the rough outline of the Converting a fridge for fermenting beer Instructable, and use a small fridge with a temperature controller placed in the crawlspace.

Step 2: Cheese Cave Materials

I managed to do this project for under $200 using a mix of new, used, and scavenged parts:

Small refrigerator, bought used on Craigslist for $60
Ranco ETC-211000-000: 2 Stage Temperature Controller $100
Honeywell TM005X Wireless Indoor/Outdoor Thermo-Hygrometer $30
miscellaneous wires and old extension cords
ceramic light bulb holder stolen from one of Randy's projects

Step 3: Wire Up Temperature Controller

Using two old extension cords, I wired up the temperature controller so that the fridge plugged into one relay, and a light bulb plugged into the other. I set the fridge's internal thermostat to the coldest setting. The light bulb is only 25 watts - if that doesn't keep the fridge warm enough, I'll put a bigger bulb in.

Next, I tested all the parameters by sticking the temperature probe in hot and cold water.

Step 4: Mount the Temperature Controller and Secure the Wires

I screwed a scrap piece of wood to the top of the fridge, and mounted the temperature controller and wires to it. I ran the temperature probe and light bulb wires in through the door and taped them in place. If this turns out to be too much of an opening, I'll drill a hole and thread them through later. I placed the remote thermometer and hygrometer in the fridge, and put the display on top of our primary refrigerator so I could check on the conditions in the cheese cave every time I walked through the kitchen.

Step 5: Install a New Outlet

There wasn't an outlet near where I wanted the fridge, so I installed one. It's not impossible for this area to get wet, so I choose a GFI. Like all my electrical or plumbing projects, there was something wrong upstream that ballooned the time required for this small chunk of the project. In this case, the newly installed GFI had an open ground, and I had to trace the problem two junction boxes away to find the bad connection.

Step 6: How to Increase the Humidity in Your Refrigerator

Increasing the humidity in the fridge was a simple matter of adding water. One yogurt container filled with water brought the refrigerator's humidity to 60%, which wasn't much above ambient. Three containers, as seen in the images, brought it up to my target of 80%. If three didn't do it, I planned to expose even more of the water's surface area by floating a sponge in the water or using some gravel or rocks.

When the temperature controller runs the fridge, the humidity usually drops 10-15%, but climbs back up to around 80% in under an hour. Since it's cool in the crawlspace, the fridge doesn't turn on much at all, and the temperature stays right around 55°F.

Step 7: Get Cheese, Start Aging

To start the cheese-aging process, I purchased a full wheel of Achadinha Capricious goat cheese. The wheel was made in June 2009 and so is already aged 9 months. I choose Capricious because as if it's some of the best cheese I've tasted in the US. I figure for my first test, I should start with something excellent. With my cave now setup, I plan to add a wheel of sheep's milk cheese and some others as soon as I can.

Donna Pacheco, the Achadinha cheesemaker, says she oils the Capricious wheels weekly with olive oil when they're young, and monthly as they age to reduce drying. She also stores them on their side and regularly rotates them. So, I oiled my wheel and set a repeating calendar event to remind to rotate and re-oil monthly. When I get more wheels of cheese, I'll build a rack to hold them on their side; for now, the first wheel is laying flat.

I'll post results in a year or so!

Step 8: Pictures of Cheese at Various Ages

This step has pictures of the cheese at various ages.

2010-11-03 The weight of the cheese is now 4.5 pounds. When I first received it at 9 months old, it was 4.75 pounds.

2011-08-14 Cheese now weighs 2058 g.