I bought this kit on Amazon to make the tofu: https://www.amazon.com/gp/product/B0035T92JS/

I used two quarts of unsweetened soy milk from the store and about 2 teaspoons of the coagulant. It didn't come out as firm as I would have liked. In the future, I will strain the curds before putting them in the mold to get more water out and I might add a little more coagulant.