Agromisa 
Interdev Agroalimentaire  

Preparation of soybean milk

	Type de fiche	Techniques/Technologies
	Mise en œuvre	Agromisa(Pays Bas)
	
	Zone géographique	; 
	Mots clés	LAIT DE SOJA; ETUVAGE; SOJA

	Public(s) cible(s)	Individual households of cottage industries

Contexte
Soybean is a nutritive product with a lot of protein. However, it is difficult to use the beans directly: They have a bitter taste and they contain proteins that inhibit growth in both man and animals, the so-called "Trypsin inhibitor" and the hemagglutins. Steaming or boiling soybeans at 100 oC breaks down both the trypsine inhibitor and the hemagglutins. It is therefore recommended to boil soybean milk for 5-10 minutes before consumption.Soybean milk can substiute cows milk in the diet of young children, it contains roughly the soame quantities of proteins and fat. Howevr, calcium, iron and vitamins A and C have to be added to constitute a  weaning food for children. By adding flavours a type of softdrink can be made. For example in Honk Kong, soya milk is produced, flavoured, bottled and sold locally. 
Problématique / Objectifs
Soya milk is a traditional product from China, where it is used as the raw material for tofu (soybean curd, see linked experience).
Description/Mise en oeuvre
Soak 500 g of yellow soybeans in 2 litre of clean water for 18-24 hours. Remove the soaking water and discard. Wash the soaked beans twice in clean water. Mill or mash the soaked and washed beans. For  milling, use a meat mincer (meat crusher) with three sieves. The holes of the sieves should be 5 mm, 3.5 mm and 2 mm respectively. First grind the beans with the 5 mm sieve and collect the milled beans in a large bowl. Add 1000 ml of clean water and stir very intensively. Filter the mixture through a cloth (60x60 cm). Squeeze out the maximumquantity of milk by pressing the cloth by hand or with a handpress. Repeat the procedure twice with the residue left in the cloth, first with the 3.5 mm sieve and then with the 2 mm sieve.The milk of these three treatment is combined, and sieved again through a clean cloth. The total yield of soybean milk after three millings is just below 3000 ml, and has a dry matter content of around 7%. If no meat mincer is available, mash the soaked and washed beans as possible in a big wooden or stone mortar with a wooden pestle. Remove the pounded mass into a bowl and add 1 liter of clean water. Use part of the water to rinse mortar and pestle, and pour the rinsing water ionto the bowl with pounded mass. Mix very intensively and filter through a cloth. Repeat this procedure of pounding, adding water and filtering two more times.Combine the three batches of milk and filter once more through a clean cloth. The total yield of soybean milk is about 3000 ml. The soybean milk can be preserved by heating in steam during 60 minutes. Pour the soya milk into bottle with a skrew lid, Fill not higher than 4 cm from the top to prevent overflowing. Put the lid loosely on the bottle. The bottles should be placed in a big pan on top of a stand made of copper gauze that is 4 cm high. Pour water into the pan to a height of 5 cm from the bottom. Heat the pan till the water boils vehemently, and count this moment as the beginning g of sterilization. Stop heating 60 minutes later and screw the lids tightly on the bottles. Seal the lid airtight with solid paraffin, wax or strong cellotape. Soyamilk prepared in this way can be stored up to 2 years.Source: Small-Scale and Home Processing of Soya Beans with Applications and Recipes by Thio Goan Loo. KIT, Dept. of Agr. Res.(1978).
Résultats/Eléments chiffrés
500 g of soybean yields 3 litres of soya milk
Enseignements
Key Factors
- Cooking to denaturate growth inhibiting proteins
- Soaking for 18 hours to remove bitter taste
- Milling between stones or in a meat mincer, or pounding with mortar and pestle. 
- Filtering. 
- Sterilising

Auteur : Rob Witte
Saisie le : 23/11/2001 

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