Soak the soya beans in water for at least 3 hours, or overnight. Drain and wash the beans. Puree the beans in a blender until smooth.
Strain the blended soya beans through several layers of cheesecloth, or a fine lightweight cloth. You may have to do this in batches. You will also need to knead the cloth a bit to get all the soya milk out.
Place the soya milk in a thick bottomed pot and heat slowly. Stir often as the soya milk burns easily at the bottom of the pot. Bring the soya milk to a boil and turn off the heat. When the milk bubbles, be careful, it will probably over flow.
Mix the gypsum and tapioca flour with the 3 tablespoons water until smooth. Have a clean container for your tofu ready next to you.
When the soya milk cools to 80 degrees C(180 degrees F). Stir the soya milk well so it swirls and dump in the gypsum paste. Quickly pour the soya milk into your desired tofu container. Be quick as the tofu will set in a matter of seconds. Let the tofu set at room temperature for about thirty minutes.
Make the ginger tea by placing the 5 cups water, sugars and ginger in a pot and heat to a boil. When the sugar is dissolved, turn off the heat and let steep for 30 minutes. Strain out the ginger.
To serve, scoop out some tofu into a bowl and pour in the warm ginger tea and eat.
Gypsum powder (calcium sulfate) can be found in traditional Thai pastry shops or Chinese groceries.
The tofu can be stored in the refrigerator, but will get less silky as time goes on.