Wash and soak (uncovered) the soybeans in 2½ liters of water (room temperature) for 8 hours.
Once they're done soaking (save the water), add 1 ladle of soybeans and 2 ladles of the water used to soak the soybeans into a blender.
Pour the blended soybeans into a large sieve. Use the back of the ladle to compress the blended soya beans against the sieve to extract the soy milk.
Strain the soy milk into a separate pot using a muslin cloth or cheesecloth to filter out any remnant fine particles.
Use your hands to gently squeeze out the soya milk. Then remove the soybean pulp from the muslin cloth and set it aside.
Repeat the steps above until you have used up all the soy beans.
Strain the entire batch of soy milk one final time into a clean pot through a clean muslin cloth or cheese cloth to filter out any remnant fine particles.
Wash the pandan leaves and fold them into 2 bundles of 6 leaves each (1 for the syrup and 1 for boiling the soy milk).
Add 1 bundle of pandan leaves to the pot of soy milk and set the pot to boil over medium heat, stirring it constantly until it bubbles.
Remove the pandan leaves and discard. Then turn the heat to medium low and continue to simmer for about 20 mins, while stirring constantly to ensure it doesn't burn.
In a separate small pot, add the sugar, 1¼ cups of water and the other bundle of pandan leaves, and bring to a boil.
Once the sugar melts, turn off the heat and remove and discard the pandan leaves.
After 20 mins, remove the soy milk from the heat. It is now ready to be served hot or chilled. Add the syrup according to your taste. You may also add some almond essence to taste if that is your preference.