Rinse the soybeans (baektae) thoroughly and soak them for at least 8 hours.
Remove the skins from the soaked soybeans.
Pour water into a pot and boil the soybeans.
Blend the boiled soybeans and water until smooth in a blender.
Strain the mixture through a sieve to get smooth soybean milk.
Chill in the refrigerator before serving.