Using earth power to keep food cool, but not too cold.

Here’s a cheap way to keep food cool during the summer and far from freezing in the early winter months. The earth acts as a huge heat sink, staying cool in the summer and remaining warm in early winter.

That’s why your basement stays cooler in the summer and why early people used caves to store food. I don’t have a cave at Bob Lake, so before I got my Sibir propane fridge (and later, my DC-powered SunDanzer fridge), I used a hole in the ground to store food. If a little inconvenient, it did work very well. This is a decidedly low-tech project but, with the addition of an indoor/outdoor wireless thermometer, you can pretend that your new cooler is ready for the digital age.

The hole is designed to fit four Rubbermaid Roughneck Storage Totes (37.9 litres). If you use other totes, just make sure they’re all the same size. This project is simple and the hardest part is digging the hole—try buying beer and inviting friends over with their shovels. Once the hole is finished, install the cooler box and backfill carefully. That’s it.

And here’s the temperature data from fall 2004, if you are skeptical. I monitored temperatures in the cooler with my wireless thermometer and I was amazed. On December 5, with enough snow and ice on the lake to allow safe snowmobiling and a week of temperatures ranging from a daytime high of -24°C to an overnight low of -30°C, the cooler’s temperature was hovering at -0.4°C. Hardy vegetables—potatoes, onions, turnips, cabbage, carrots, parsnips and the like—keep fine at this temperature. I put four heads of cabbage in a Rubbermaid container in the hole to prove it. That means we could have easily stored vegetables in the ground for eight weeks, from early October to early December. Not bad for a fridge that costs about as much as the used one you have in your rumpus room to store beer.

So if you are on a budget and not ready to buy a propane fridge or a DC electric fridge for your cabin, or you just need a little more storage space, start digging. 

One Step More — Here’s one idea that I haven’t tried but I know will work. When I was building houses for a living, we would place several inches of Blue SM stryfoam at the level of the cement footing extending away from the building. The idea was to keep the frost from penetrating under the footing where it could freeze any moisture and keep the footing from cracking. On the same theme, excavate around the outside top of the cooler hole to a depth of about 8 to 10 inches. Slope the soil with a slight grade so that the water will run away from the hole. Fit the hole with Styrofoam and cover it with about four inches of the excavated soil and that’s it. This should keep the frost from going down into the ground or the cooler and should keep warmth in during the winter. It should also help keep heat out during the summer. 

As seen in the May/June 2006 issue of Cottage Magazine