Boil water in a kettle. It should be enough for the water bath. Set aside.
Prepare a pot and place it on top of the stove. Place a heat-proof bowl big enough for 500ml of liquid in the middle of the pot.
In a small cup, dissolve cornstarch in 1 tablespoon tap water then add the Epsom salt and stir until dissolved.
Pour the Epsom salt mixture into the empty bowl. Add the soy milk to the mixture in a steady stream, not too fast but not too slow. Do NOT stir! Once both mixtures are combined, try not to agitate it or it will not curdle as smoothly.
Now, pour the boiling water into the pot, careful not to pour any to the bowl of soy milk, just high enough to be on the same level of the mixture in the bowl.
Cover pot with the lid that is covered with clean cloth to absorb the steam and prevent it from dropping back into the Taho mixture.
Turn on the stove to very low heat and let it cook in a gentle simmer for 15-20 minutes or until the Taho becomes firm to the touch but wiggly. Avoid letting the water boil or the mixture will also boil and will never set. While waiting for the Taho to cook, prepare the arnibal and tapioca pearls.
TO MAKE ARNIBAL: In a small pot, combine equal parts of brown sugar and water. Bring it to boil over medium heat while stirring occasionally and let it simmer until it thickens into a syrup (about 7-10 minutes).
TO COOK TAPIOCA PEARLS:
Boil a half liter of water and add the tapioca pearls. Let it cook for 10 minutes. Place a colander/strainer in a bowl or pot and pour the contents to separate the tapioca from the water. Use the same water and bring it to boil the second time. Wash the strained tapioca pearls thoroughly with tap water and put it back into the boiling water and cook again until they become completely translucent and no more white spot at the core.
Using a wide spoon or ladle, make thin scoops of Taho and transfer to a glass. Add some arnibal and Tapioca pearls. Enjoy while warm.
Note 1. The amount of Epsom salt may vary depending on the soy milk you are using. Try it first using a lower amount from ¼ teaspoon for 1 cup of soy milk. Add more if it does not coagulate. But not too much as Epsom salt is also used as a laxative.