Rinse soybean, then soak for at least 5 hours or overnight (keep refrigerated if overnight). Drain off.
Add 1 part of soybean and 3 parts of water into a blender (the ratio of bean and water is 1:3).
Blend with HIGH speed for 1 minute, rest for 15 seconds (to avoid overheating), then continue blending for another minute until very fine.
Pour into cloth filter bag, then repeat the same process for the remaining soybean.
Tie the filter bag, then squeeze out the soy milk completely.
Strain soy milk again into large thick bottom cooking pot (I use 5-Liter stainless steel pot), add in pandan leaves.
Start with HIGH heat, stirring constantly. When foam has built up (after about 5 minutes), turn to MEDIUM heat and continue stirring. When foam has risen to the rim of pot, OFF the heat. When foam has gone down, heat up again over MEDIUM heat. Repeat the steps until soy milk starts to boil. When soy milk has boiled, reduce to MEDIUM-LOW heat and continue cooking for 5 minutes. (The whole process takes about 30-35 minutes. Time suggested is only for reference as the heat for different cooker is different.)
Sweeten to taste with sugar (optional). Keep refrigerated and consume within 3 days.
Video
Notes
This recipe yields 2000 ml of soymilk divided into 8 servings. The nutritional value for reference is for 1 serving of 250 ml soy milk WITHOUT sugar . Reminder (to reduce the chance of burning):1 Use cooking pot with thicker base to cook soy milk will allow heat to be distributed more evenly.2 Start with HIGH heat, when foam has built up, reduce to MEDIUM heat immediately.3 Stir constantly during the whole process to allow heat to be distributed evenly.4 You may also cook soy milk using microwave, please refer to: Homemade Black Soybean Milk (No Soy Milk Maker)