1. Heat 1L of soy milk to 80 degrees in a large pot. Meanwhile put Nigari in a microwave-safe small bowl and add water. Microwave for about 10 seconds to dissolve nigari. Set aside. Once the temperature of the soymilk reaches 80 degrees, remove it from heat.
2. Add the nigari (coagulant) mixture to the soy milk. Stir gently 2 or 3 times (no more) and let it sit for about 20 mins.
3. Line a tofu press mold with a clean cotton napkin(cloth) and set it over a plate or in the kitchen sink. Transfer the tofu mixture into a mold lined with a cloth. Fold the fabric and put weight down on the top of tofu mixture to press out the liquid. Keep it there for about 20 to 30 mins.
4. Remove the tofu from the mold and soak in the clean water for about 1h to mask the bitter taste of nigari.
Serve as it is, or in a miso soup, or any other...!