How a zeer pot fridge makes food last longer
In the heat of Sudan, food doesn’t stay fresh for long. Tomatoes go off in just two days. After four days carrots and okra are rotten. For poor families in North Darfur and Blue Nile State, without any means of preserving their crops, this can lead to hunger and even starvation. The situation is especially grave for those most vulnerable like children and elderly family members.
One ingenious solution is the zeer pot: a simple fridge made of local materials. It consists of one earthenware pot set inside another, with a layer of wet sand in between. As the moisture evaporates, it cools the inner pot, keeping up 12kg of produce fresh for up to three weeks.
Fruit, vegetables, water. The zeer pot keeps them all fresher for longer – providing much needed help to starving families.
You can see from the table below the incredible difference that a zeer pot makes to food preservation in Sudan. For many families, it can mean the difference between potential starvation and having enough food to feed themselves.
A simple technology that brings fresh hope
For the last eight years, Practical Action has been helping local people to make these life-saving refrigerators.
1 First, bowl-shaped moulds are created from mud and water – and left to dry in the sun. Clay is then pressed onto the moulds to form the desired size of pot. Clay rims and bases are added and the moulds are removed. The pots are left to dry in the sun. |
2 Once the pots have been fired in a pit of sticks, the zeer pot is ready to assemble. A smaller pot is placed inside a larger one, and the space in between filled with sand. |
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3 The whole structure is then placed on a large iron stand. This allows the air to flow underneath and aid the cooling process. |
4 Twice a day, water is added to the sand between the pots so that it remains moist. The entire assembly is left in a dry, ventilated place. |
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5 Fruit, vegetables and sorghum – a type of cereal prone to fungal infestation if not preserved – are then placed in the smaller pot, which is covered with a damp cloth. |
6 In the heat, the water contained in the sand evaporates towards the outer surface of the larger pot. This evaporation brings about a drop in temperature of several degrees, cooling the inner pot and extending the shelf life of the perishable food inside. |
Further information
Clay refrigerator
Detailed background and instructions on how to make a zeer pot clay refrigerator
Clay-based technologies manual
A practical handbook on making clay refrigerators, water coolers and stoves, from Practical Action Sudan. This manufacturing manual has step by step instructions, photos and technical drawings.
Evaporative cooling
Download a technical brief on evaporative cooling from Practical Answers
A zeer pot ceramic fridge in cross-section. Download PDF version
Case study
Produce | Shelf-life | Shelf-life |
|---|---|---|
Tomatoes | 2 days |
20 days |
Guavas | 2 days |
20 days |
Okra | 4 days |
17 days |
Carrots | 4 days |
20 days |
Rocket | 1 day |
5 days |
In the hot weather of Sudan, Hawa Abbas used to lose half of her tomato, okra and carrot crop.
Her world changed when she began working with Practical Action. As she herself says, “After many years of struggle, Practical Action came and showed us how to make pottery refrigerators. They are made of two different size pots. The smaller is put inside the bigger one and in between we put sand and wet it with water and cover it.”
“They keep our vegetables fresh for 3-4 weeks, depending on the type of crop. They are very good in a hot climate such as ours where fruit and vegetables get spoiled in one day.”
It is clear to Hawa Abbas how important this has been to her family. “Since I learned how to make zeer pots our life has been so much better.”
Video: click on the video player (right) to view a short demonstration of the zeer pot fridge in action.
Just £30 could buy three zeer pots, and help improve people's lives. If you are able to, please make a donation to Practical Action's work today.
