Transfer the soy milk in a heavy bottom pan, else it may start to burn at the edges. You can also use a double boiler.
Bring the milk to a boil while stirring constantly to avoid sticking at the bottom.
You will notice some foam build up, remove it as and when you notice and keep stirring.
Once its boiled, turn of the stove and let it cool for 2 minutes while stirring.
Slowly add the coagulant, while stirring the milk in circles or the direction of the number 8
You can stop stirring as soon as you notice the milk has separated and curds are forming.
Stop adding the coagulant (and stirring) when water turns clear. If it is still milky, then you may need to add more coagulant.
Cover this with a lid and let it rest for 10 minutes.
Now use the tofu mould or the DIY mould. For DIY option, (shown in the video) place a large bowl (enough to catch all the water that will drain) and then put a colander on top. Also place the cheese cloth on the colander.
pour all the content in this and tightly pack the tofu with the help of the cheese cloth in any desired shape.
place some weight on this (500g to 800g) and let all the water drain out. The longer you keep this, the firmer tofu gets. Ideal time is about 20 minutes as I do not like this too hard. If you want very firm, you can keep the weight on for up to 40 minutes.
once the water is drained, remove tofu from the cloth and place in a bowl of cold water until you want to consume this.
To store, you can keep in an airtight glass/ceramic container, dipped in water for about 3-4 days in the refrigerator. I prefer to use fresh on the same day.