There are various of methods for preserving food and keep it cool in summer. In the outdoor the most practical methods are:
- pit coolers
- Dig a pit 50 centimetres large and 90 centimetres deep in the ground, in a shady location.
- Support the sides of the pit by placing thin branches or wide bark strips.
- Fill half of the pit with pebbles from a stream bed or tiny rocks of any type.
- Twice a day pour 2-3 buckets of water onto the pebbles and place the food containers on the top of them.
- To protect from the above ground heat, carefully cover the surface of this storage pit with soaked newspaper sandwiched between two layers of wet cloth.
This kind of cooler may have an inner temperature of around 10° C below the outside air temperature.
To make an evaporation cooler:
- Place the container that will contain the spoilable food over few flat stones inside a stream
- As a precaution, weight down the container with rocks.
- Pack food which can be spoiled by water in waterproof containers before placing in the cooler.
- Use a cloth to cover the container so that the ends hang down into the stream, absorbing water to maintain the container and its contents cool.
You can make another type of evaporation cooler by hanging a small container under a bucket suspended from a tree.
- Fill the bucket with water, cover the bucket with a large cloth and sink it to the bottom of the bucket by putting a heavy rock in its center.
- Drap the ends of the cloth over the sides of the bucket and down over the food container directly below, which is kept fresh by evaporation, assisted by any air flow which is blowing.