Rinse the black beans thoroughly and soak them for at least 8 hours.
Discard the soaking water and rinse the beans again.
Place the black beans in a pot with plenty of water and boil them.
Drain the boiled beans and let them cool.
Blend the boiled black beans with water until smooth.
Strain the blended mixture for a silky texture.
Pour the strained soy milk into a pot and cook over medium heat for 5 minutes, stirring constantly.
Add salt or honey to taste and serve.