Alternative Refrigeration Techniques for Food Storage
A refrigerator is perhaps the most common appliance in every household kitchen. Without it, most of us would have no idea how to keep our food fresh and preserved. Refrigerators, however, use tremendous amounts of electricity and are one of the most energy-intensive appliances in our homes. Might there be other ways to preserve our food without relying on fossil fuel energy supplied by a refrigerator?
The Energetic Cost of Running a Refrigerator
One hundred years ago, the milk we drank and the produce we ate had to be consumed in a relatively short amount of time. Since most people lived in rural areas and either had a family dairy cow or tended their own gardens, long term storage wasn´t much of a problem. Whatever milk wasn´t drunk during the day was either fermented into cheese or fed to the hogs because bright and early in the morning a fresh supply of milk was only a “walk to the barn´s” length away.
As our society has grown increasingly urbanized and ever less agrarian, however, we heavily rely on refrigeration for our food. The produce that is picked from a farm in Mexico is loaded onto refrigerated trucks, flown to the United States in refrigerated airplanes, distributed across the country in refrigerated trailers, stored in refrigerated bins at the grocery store before eventually making it to our own refrigerator.
In many ways, refrigeration has allowed for the globalization of our food supply. If it weren´t for refrigeration, we´d be stuck choosing from brown bananas and wilted lettuce at our local grocery store. If you enjoy fresh strawberries in the dead of winter, you have refrigeration to thank.
The problem with our utter reliance on refrigeration techniques is two-fold. Firstly, this dependence gives rise to massive amounts of vulnerability. The supply line to get the food from where it is grown to our refrigerators or dinner tables is so long that any number of potential threats could disrupt that process and create mass food shortages.
Secondly, refrigeration depends heavily on fossil fuel energy. As we approach, or have already reached, peak oil, it becomes evident that our civilization urgently needs to begin weaning itself off fossil fuel dependence. When the oil runs out, how will we refrigerate and/or preserve the food we eat along the supply lines until it gets to our homes?
Do We Really Need Ice Cubes?
The root of the problem, of course, isn´t really refrigerators in themselves, but rather the way globalization and consumerism have shaped our civilization. The globalization of our food industry has made it so that a piece of food travels an average distance of 1500 miles before reaching our plate.
We have lost almost all contact with any sort of bioregional limitations to what we consume. If we want grapes in December, then we expect that our globalized food system will ship grapes from Chile. Some would argue that instead of eating fresh grapes, fermenting those grapes from our summer harvest into wine is a much better way to extend the harvest!
In recent years, the emergence of the local food movement has begun to counter the globalization of our food system. Farmers markets, community supported agriculture and other such institutions that connect consumers to local producers are helping people to reconnect with what is grown within their community and the people who grow their food.
One of the most common ways throughout history of preserving food from the harvest was with a root cellar. Many older homes have a “cold room” built into the basement. On old farmsteads, you might also find a mysterious door that leads into the side of a hill. These cold rooms or root cellars were essential parts of the farm and helped farm families keep an essential food supply throughout the winter months.
The temperature of the earth just a few feet beneath your feet is usually a comfortable temperature somewhere between 45 and 55 degrees Fahrenheit. The exact underground temperature will depend on the average temperature of the area where you live, but will always be substantially cooler than summertime temperatures and warmer than the freezing temperatures of winter.
This constant and cool temperature within the earth is a little bit warmer than most refrigerators, but still plenty cool to keep many foodstuffs preserved for the long run. Additionally, most underground cold rooms and root cellars have a humidity rating that is like that of a refrigerator. The combination of cool temperatures and the right humidity can keep your food preserved.
While you might not be able to preserve meat, a root cellar or cold room offers a cool enough temperature to preserve most types of produce, cool your wine, and keep fruit fresh and crisp. In cooler zones, you might even be able to keep milk, yogurt, and cheese for several days before they begin to go sour.
Building your own root cellar is a straightforward and simple process that even a novice builder can accomplish. You are simply looking for a way to “bury” a space in the ground where you can store your food and still have easy access.
One of the easiest root cellars to build is to simply take an old refrigerator, dig a hole that is about twice the “depth” of the refrigerator and lay the refrigerator into the hole on its back with the door facing upwards. You can build 2 or 3 steps to make it easier to go down where your refrigerator/root cellar is. Simply build a set of hatch doors over the entrance way and you have an easy to use root cellar made from a recycled refrigerator.
If you want a larger root cellar and are a more ambitious builder, you could consider building a root cellar right into the north facing slope of a small hill. You want to choose the north facing slope (in the northern hemisphere) because that slope will receive much less sun keeping the temperatures down. A shady area would also be a plus.
With a small backhoe, or a hoe and a strong back, you will need to dig into the hillside anywhere from 6 to 12 feet. It is best (and safest) to find a hill or cutout that isn´t much taller than you are. Once you’ve dug your hole, you will need to lay cinder block on three sides and pour a cement floor. For the roof, you can lay strong timber such as cedar round poles on top of your cinder block walls. Cover those round poles with pond liner or some sort of impermeable material and cover your roof with 2 to 3 feet of the excavated material. This will make sure that your root cellar stays cool as it is still technically underground.
Clay Pot Refrigerator
A clay pot refrigerator, also known as a pot-in-pot refrigerator is a simple, powerless device that uses the principle of evaporative cooling to keep foodstuffs fresh and cool even in the hottest temperatures. This simple “appropriate technology” was developed by international development organizations searching for ways to help rural villagers around the world without access to electricity find ways to preserve their food.
A clay pot refrigerator utilizes a porous outer earthenware pot, lined with wet sand or other substrates, and an inner pot (which can be glazed to prevent penetration by the liquid) where food is placed. The evaporation of the outer liquid (contained in the sand or other substrates) draws heat from the inner pot.
You can make a clay pot refrigerator in many sizes, from a small pot that just holds a gallon of milk to a full-sized refrigerator. This simple technology requires only a flow of relatively dry air and a source of water to keep your foods preserved.
Living without a refrigerator first requires us to call into questions some of the ideas about our livelihoods and lifestyle. Once we realize that it is possible to live without ice cubes or grapes in December, we might be able to find other more ecological refrigeration techniques. Building your own root cellar or a clay pot refrigerator are two simple technologies that can allow you to find ways to preserve your food while freeing yourself from dependence on fossil fuel powered refrigerators.