The vegetable soy drink is simple to prepare at home and in this way you can check the origin of the soy which is important that it is organic and possibly local.
Soak the soy (150 g) for 12 hours, changing the water a couple of times. Then blend it in 1.5 l of fresh water and bring the mixture to a boil, allowing it to boil for about twenty minutes. Then blend with an immersion blender and leave to cool, finally filter with a food cloth (etamine, or not too thick cloth) and pour the soy drink into a glass bottle that you will keep in the refrigerator for up to 3 days. With the soy waste, which is called okara, you can make meatballs, biscuits or other doughs. Here
you will find a cookie recipe.