Soak soybeans in plenty of cold water for about 12 hours or overnight.
Pour off the soaking water and rinse the soybeans with clean water.
Place the soybeans and 500 ml of clean water in a blender and mix to a homogeneous mass.
Pour the mixture through a cheese cloth, collecting the soy milk in a clean container, and squeeze out the soy mixture in the cheese cloth.
Put the pressed residue back into the blender, add another 500 ml of clean water and mix again to a homogeneous mass.
Pour the mixture back through a cheese cloth into the first portion of soy milk and squeeze it out thoroughly.
Pour all the soy milk and salt into a saucepan with a thick base, bring to the boil over a low to medium heat, stirring constantly, and then simmer for approx. 15 minutes, stirring occasionally.
Add agave syrup and stir.
Pour the soy milk into a sealable glass bottle, leave to cool and then store in the fridge.
Shake the bottle with the soybean milk before each use.