Most of us are used to having a refrigerator in our homes to keep food and drinks safely cool. However, people throughout the centuries didn’t have these appliances to keep their food in good condition. There are ways to keep food cool enough to be safe for eating, and you don’t need to power them with electricity.
They may not be as cold as an electric refrigerator in some cases, especially when it’s extremely hot outside. Whether you’re trying to reduce your electricity use, or you’re in a situation where power isn’t available, here’s some information about refrigerating without electricity.
The vast majority of non-electric cooling methods use evaporation to keep food at a comfortable temperature. Working a lot like evaporative air conditioning, these methods have been used for a long time. One common type is a pot in pot fridge, also called a Zeer pot. These devices were invented in the mid 1990s to provide cheap, efficient cooling in areas without access to electricity, such as Nigeria. However, they’re using principles that have been around in a long time.
To make one of these “fridges”, you’ll need two unglazed pots made from terracotta. One should be larger than the other, and any drainage holes need to be plugged firmly. Put a layer of sand into the bottom of the large put and place the smaller one inside, then fill the gap (it should be about an inch on all sides) with sand. The sand should come up to just below the rim, and there should be enough sand on the bottom to keep the rim of the smaller pot level or a little lower than the larger pot.
Now, pour water on the sand until it begins to pool on the surface, then put the pots in a shady area with good ventilation. Putting them on plastic will prevent seepage through the bottom. Put the food you’d like to keep cool inside once the pots have cooled down, remembering to wrap each item individually. Place a wet tea towel or similar fabric on top of the smaller pot as well. The water soaks into the terracotta pots, then evaporates out of them. This process cools the pot, the sand, and the contents of the pots. Remember that these pots work best if there’s little humidity in the area – hot, wet areas will result in much less effective cooling.
It may take a while for a temperature drop to occur if the area you’re in is very hot or your pots are thick walled. Round pots may work more effectively than rectangular ones. The nice thing about the Zeer pot over other evaporative cooling methods is that air movement is unnecessary. After the pots are “charged” – that is, soaked through with water – you’ll need to pour around a quart of water a day on them to keep the sand moist, but that may vary according to your area. Just make sure nothing is dripping.
This kind of refrigeration won’t keep items inside extremely cold, but it will slow spoiling and keep thing much cooler than the ambient temperature. In one test in Australia, the interior of the pots was around seventy-seven degrees Fahrenheit. That may not sound cool, but if you consider that the ambient air temperature outside was closer to a hundred and fifteen, it’s an impressive drop! Since there are no moving parts, this kind of fridge doesn’t break, and it’ll allow you to keep fruits, vegetables, baked goods, eggs and dairy for much longer. It isn’t usually cool enough to provide safe temperatures for raw meat and fish, however.
Photo by: Michal Adamczyk -