Zeer Pots, Wave Of The Past.Posted: June 11, 2012
So. In addition to being obsessed with how things work in the kitchen, I also like to figure out how tangible things work outside of it. For example, one time I thought it would be fun to try to adjust the brakes on my 1976 VW bug, since they needed a tuning anyways.. which led me to my next two realizations that I am both deeply afraid of cars slipping off of jack stands and that it is possible to drive a car using your emergency brake to stop in order to get to the closest mechanic.
Anyways, you’re clearly thinking that this has nothing to do with cooking, right? Hang tight, I’m getting to it.
As I was writing, I like to figure out how stuff works, and because of the way that my day is structured I often times have a whole ten, twelve minutes at a stretch to sate my curiosity about whatever it is that I’m interested at that moment. Why, just the other day I was busy reading Lifehacker, trolling for new things to be interested in when I came across this gem. Enter the zeer pot, a nonelectric refrigeration system, wave of the past.
I wondered how could something that essentially is no more than two pots and some wet sand keep anything cool, really. Or, perhaps more accurately, I wondered how anything could be kept cooler more efficiently than being stuck IN the wet sand. Naturally, I found my next thing to occupy a good ten minutes of my life, research wise.
Zeer pots, which have been used since the dawn of recorded time, work simply on the concept of evaporative cooling. Evaporative cooling has been used in a variety of formats dating back to the Old Kingdom of Ancient Egypt for both refrigeration purposes as well as air conditioning purposes. Ancient Persians are credited for inventing the first swamp cooler (called a windcatcher), Egyptians used zeer pots to keep their perishables from spoiling, even early American aircrafts used evaporative coolers in some of their engines Evaporative coolers are simple to make, effective and efficient, which makes them perfect for situations where energy expenditure may be a luxury.
The way evaporative cooling works is simple. In the case of a zeer pot, a larger porous vessel is partially filled with wet sand. Next, a smaller pot (which does not need to be porous) is nestled in the center of the larger vessel and more wet sand is added to the space between the larger and smaller vessels. To get the water to evaporate, latent heat is drawn from the surrounding air, which produces a cooling effect near the sand (such as in that small pot).
These simple refrigerators are still used in some parts of the world, especially in developing countries where electricity is sporadic and food borne illness may be higher. Although they aren’t the miracle answer to refrigeration, the zeer pot can increase the shelf life of perishables for two or three times of that if it were sitting on a countertop somewhere.
It goes without saying that when using a zeer pot that you won’t keep a brick of peas frozen to subzero hardness or that your ice cream won’t melt, but they can be pretty useful for things like keeping fruit and vegetables chilly while out in nature somewhere. It’s also a neat little science geek trick to whip out at your next barbecue, impressing the ladies with your homemade environmentally friendly cooler.
Now, onto figuring out how to install a nitrous system onto my hooptie…