We can plan to grow our own food and raise our own livestock but let’s face it, many of us are not prepared to use salt or smoke to preserve butchered for long periods of time. And cooking it all at once doesn’t really help much if there is no way to keep leftovers from spoiling before they can be eaten. The same is true for dairy products such as yogurt, cheese, butter, and fresh milk. It just needs to be kept cool to keep it from spoiling in the hot weather.
Zeer is an Arabic word that translates as large pots. The concept of evaporation for cooling purposes existed as far back as Ancient Egypt, where water was kept cold in large clay pots. The zeer pot is an evaporative cooling device, re-invented in Africa by a Nigerian teacher, Mohammed Bah Abba. In Africa, the pots were made from a mud mixture and hardened in the sun or fired in a pile a cow dung and sticks.
Residents of cool, dry climates will find that with a continual breeze blowing on the pot, they can even get the internal temperature to 40 degrees Celsius, very much like an electric powered refrigerator. In fact, unless you live in a very hot and humid climate, a zeer pot will work surprisingly well. When done properly can extend the shelf life of food anywhere from 5 to 10 times when compared to room temperature storage.
Steps for Making a Zeer Pot
- You will need to find, purchase, or make two pots from terracotta or clay. Use only unglazed pots, the sides must be sufficiently porous to allow for evaporation. Glaze on the inside of the smaller pot is okay.
- One pot should be large enough for the other pot to fit inside it and have at least an inch to an inch and a half space all the way around. If your found or purchased pot has a hole in the bottom, plug it with putty or tape or even better use a 4” long bolt along with nuts and washers to bolt the smaller pot to the large pot and then seal with silicone.
- Add an inch of coarse sand to the bottom of the larger pot. You want to create a base so that when the smaller pot sits on it, the top of the two pots are level with one another.
- Once you have the smaller of the pots positioned on the base of sand, fill the space between the two pots with sand until you have only a small gap around the top edge.
- Gradually add water, preferably cold, over the sand between the two pots until it is thoroughly wet and unable to absorb any more water.
- Cover the top of smaller pot completely with a wet towel or cloth.
- The smaller pot should start to cool down. You can use a thermometer placed inside the small pot to gauge this or feel it with your hands.
- Place your fruits and vegetables or other items needing refrigeration into the smaller pot and replace the wet towel over the top.
- Store the zeer pot in a dry place that is well-ventilated which will encourage the water to evaporate to the outside pot. Placing it on a stand will allow for increased air circulation beneath the pot.
- Check the pot regularly, at least twice daily, to make sure that the sand between the two pots is still damp. Add more water frequently to prevent the sand from drying out and to maintain the evaporation process which keeps the inner pot cool.
How a It Works
If you think back to the last time you went swimming on a day where it was hot and dry but still a little breezy, you may have felt comfortable while you were in the pool but once you got out soaking wet and that breeze hit you, the chill set in. As soon as you toweled off and had a few minutes to dry out in the sun, you were hot again and ready for another cool dip in the water. A zeer fridge works in a similar way as demonstrated in this video:
The wet sand between the two pots creates a thermal mass which maintains the cold temperature inside the smaller pot and also serves to wick the moisture up the sides of the pot. When stored in a shaded, well ventilated area, the water evaporating off the outside pot cools the pot. On days where a good breeze is unavailable or when storing the zeer pot indoors, you can use a solar powered fan and keep the pot cold.
- Keeps food cool without need for power
- Keeps insects away
- Fresh vegetables last longer in than in typical hot climates
- Can be portable depending on size of pots used
- You must keep a careful eye on the internal temperature to ensure that your items on being stored at a consistent temperature.
- Food items stored in a zeer pot much be checked frequently for any signs of spoilage. The life of fruits and vegetables is extended but it does vary greatly for each type of fruit or vegetable.
- The Zeer pot must be checked at least twice daily and water added to ensure the sand stays damp.
- Sunlight shining directly on the zeer pot even for a short period of time will negate the cooling effects. It must be kept in the shade and thus small in size and portable so they can be moved if needed.
- You may have to use several different ones in order to store meat, dairy, and fruits and vegetables as the interior space of the pots is quite a bit smaller than regular refrigerators.
What Can Be Stored in It
- Meat up to 14 days compared to several hours
- Fruits and Vegetables for varying amounts of time (check frequently for spoilage)
- Liquids and beverages that are better when cool.
- Millets and Sorghum to prevent growth of fungi and guard against humidity
No matter what type of event you are preparing for, the chances are that traditional electric powered refrigeration will be either unavailable or sporadic at best. If you want to be prepared to store your more delicate food items such as meats, dairy, and fruits and vegetables, consider a zeer pot as an alternative cooling device.