Hi! I just learned how to make soya since high school... Karon ra ko nakabuhat utro ato kay Im passing the knowledge to people and also Ive seen how taho makers make soya milk, the "CLEAN" way. heheheheh! anyway, here's the recipe:
you will need:
----2 cups soya beans
----3 liters water
----salt (1/4 tsp per liter) or depending on taste
----sugar (3 tbsp per liter) or depending on taste
blender
katsa (pwede man pud panyo na sterilized via boiling water,make sure it doesnt smell like downy or soap, otherwise your soya will end up downy or laundry flavored! hahaha!)
procedure:
1.
soak soya beans in water overnight
i-compare gani ang size sa dry soya ang soaked soya beans... to the left, to the left!!! hehehe and soaked soya beans.
ibutang sa blender ang beans and water para dali ra ma grind
add water if dili ma-grind tanan soya...
i-sala ang ground soya using the hanky/katsa and hutda ang water for the soya grind. If gusto kag lasyaw na soya, just add more water if you want.
here's the used soya ground
boil the raw soya milk in low heat
make sure to stir it continuously for about 25 minutes

then add salt and sugar for taste
pour soya milk in a pitcher
this is optional since RR wants choco flavored soya:
add 1/2 cup cocoa powder in hot soya (if u want, pwede milo, ovaltine, etc)
stir
best when served cold! 
enjoy!!!
trivia:
1 liter soya milk mixed with 1 small packet of gelatin powder would turn into TAHO
soya milk boiled with white vinegar turns into tokwa