As FAO site mentions : milk should be cooled immediately after milking, and be kept as cold as possible before processing. The best temperature to keep the milk is 4 degrees Celsius, but in most countries this requires some kind of cooling equipment. Water availability (that can be re-used for another purpose afterward) is a must. Some cooling methods are :

1. keep the milk in the shade not in the sun and in a well-ventilated place;
2. use cold water to cool the milk (you can for example put the milk in a water bath, or in a stream);
3. use ice to cool the milk (pay attention to milk freezing ! see comments below);
4. use the following cooling equipment :
- conventional refrigerator for small amounts of milk (freezing risk !);
- evaporative cooler;
- surface cooler;
- an in-can rotary cooler;
- bulk (direct expansion) milk cooling tank.

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We have yet to see an efficient large scale working solar milk cooling system. Here are some links :


1°) Evaporative cooling

Using a "modified" CoolKeg, this project was selected by World Bank Development Marketplace in 2008. This is a project that is still being tested (how to keep clean, recharge zeolite (see solaref below), ...)


2°) Photovoltaic solar

Solar energy in small-scale milk collection and processing

A refrigeration facility for milk cooling powered by photovoltaic solar energy

Una investigadora desarrolla un sistema de enfriamiento y mantenimiento de leche a partir de energía solar

Photovoltaic Milk Cooler


3°) Solar Ice

For safety reasons, we do not favor amonia based system when they are used on a farm or in a village chilling center.

Solaref system may be a solution for very small scale activities.


4°) Ranque-Hilsch vortex tube

Vortex tube as a possible method of refrigeration.


5°) Water cooling

How to : a continuous low cost bottle & jar cooling system

Depending on ground water temperature, the CHARRIAU's tubular cooling system can be a very efficient tool.
If energy is available at certain time of the day, you could use it to cool water then store this water in an second insulated milk cooling tank. You can then use this cold water to cool milk when required even if no electricy is available at this time.

6°) Magnetic cooling

Using Magneto-Caloric element as a possible method of refrigeration.

Dernière modification par charriau (2012-03-05 18:04)