Rinse black beans for several times, then soak them with clean water for at least 5 hours. Drain.
Put 1 1/2 cups of the soaked bean into a blender, then add in 4 1/2 cups of water (the ratio is 1:3).
Process on high speed until the black bean is very fine, then strain through a colander lined with a coffee cloth (or cheesecloth). Hold up the cloth and lightly squeeze out the milk. Repeat the same for the remaining.
Strain the black bean milk through a coffee cloth again into a large microwave-safe glass bowl.
Cook (WITHOUT lid or it will spill) on high in the microwave (1000 W) for about 40 minutes or until boiling, then continue to boil for another 1-2 minutes.
Remove and set aside to cool for a while, then strain again to remove the beancurd skin forms on top of the cooked milk.
Sweeten to taste with sweetener and serve either warm or cold.
Video
Notes
This recipe yields 1.8 quarts (1700 ml) of milk. Each serving is 0.225 quarts (213 ml). (14.3 net carbs)The nutritional value for reference is for 1 serving. Keep refrigerated for up to 3 days.