Refrigeration seems one of those conveniences that only arrived with the technological advances of electricity, but to the surprise of many, this isn’t true. We were able to keep food cool and refrigerated for centuries before every home had grid electricity. In fact, many of these methods were regularly used until the middle of the 20th Century.
Nowadays, as we are working to reduce our dependence on non-renewable energy sources, it seems a relevant time to revisit some of these ways of old. Tapping into some of the past techniques for storing food in cool spots without power seems ever more pertinent. If we could refrigerate our food without relying on electricity, wouldn’t that be just amazing?
Not only can we keep food cool without electricity, but devices for doing so can be put together inexpensively and right at home. Even better, there are no moving parts to break. These are simple, efficient systems.
1. The Root Cellar
Root cellars have been around for a long, long time, and in rural locations, some people still use them. They rely on the steady temperature of earth to keep things cool, and the insulative properties of it to prevent them from freezing. For those in need of cool rather than cold, these are a great way for storing many vegetables, ferments, and canned goods.
A root cellar can be an entire building, a room’s worth of chilled storage, but it can also be something relatively simple that’ll work in the average suburban backyard. Rather than building a room, it could be a hole that you reach into from above.
Root cellars can be created with many different, inexpensive materials: trash cans, five-gallon buckets or pallets. It’s just a matter of putting a container in the ground, covering it, and insulating the top with a good layer of straw, hay or wood shavings.
2. The Coolgardie Safe
These are really ingenious refrigerators that were the result of Australians living in the desert and needing to keep items cool. The system works on the chilling effect of evaporation: As water evaporates, it causes a heat transfer.
Essentially, Coolgardie safes are boxes with wooden framework and wire mesh sides. They have a tray that sits atop them, and wicks of cloth that partially rest within the tray and drape over the sides. The tray is filled with water, and via capillary action, the water wicks down to the hessian covering the sides of the box. Finally, the breeze blowing through the hessian encourages the water to evaporate. The heat transfer from the evaporation cools the inside of the safe.
These are great for putting out on a covered patio or balcony, where the breeze can hit them. Or, they could be put in a cross-breeze inside. They need air movement to work.
3. The Pot-in-Pot Fridge
Somewhat reliant like a melding of the root cellar and Coolgardie, there is the pot-in-pot fridge method. In this case, a smaller glazed clay pot is put inside of a larger unglazed pot. In between them, there is a layer of sand, which is kept moist. The sand itself is cool like the earth of a root cellar. The fridge is covered with a wet cloth, and the evaporation of the water from the top and sides of the unglazed pot creates the same kind of heat transfer as the Coolgardie safe works on.
Methods similar to this date back to Ancient Egypt from 2500 BCE, and possibly even earlier than that in the Indus Valley. This system, also known as zeer, works very well in arid locations where the hot, dry climate will keep the water evaporating. Too much humidity prevents it from functioning.
4. The Ice Box
Ice boxes of old were obviously completely off-grid, but the infrastructure for that these days is likely lacking. About a century or less ago, people in the north would mine ice from frozen ponds in the winter, pack them in sawdust, and send them south. The ice blocks were stored in icehouses then shipped around on barges and wagons.
Nowadays, an ice box would probably require harvesting ice from an electric freezer. However, it would make a great off-grid cooling system that could maintain cool temperatures for several days at a time. Plus, freezers require less energy than refrigerators, and they offer the benefits of long-term food preservation. Together, an ice box and a freezer could make a good team for a low-impact house or cabin.
Though seemingly antiquated next to modern fridges with water spouts, automatic ice-makers, and thermostat controls, these power-free systems could once again play a valuable role in our lives. They are worthwhile pursuits, or good knowledge to have, for hobbyists, off-gridders, and environmentalists.
Lead Image Source: Pixabay