Soak 1 cup of dry soybeans in water overnight (8–12 hours).
Drain soaked beans and blend with 3–4 cups of water until smooth.
Use a muslin cloth or nut milk bag to strain out the soy milk. Keep the liquid, discard or reuse the pulp (okara).
Bring the soy milk to a gentle boil. Stir occasionally and remove foam.
Turn off the heat. Stir in 2–3 tbsp of lemon juice or vinegar gradually. Let it sit for 10–15 mins until curds form.
Pour the curds into a muslin-lined colander. Let it drain for 10–15 minutes.
Wrap the curds in cloth, place a weight on top, and press for 15–30 minutes depending on how firm you want it.
Your tofu is ready! Store in cold water in the fridge and change the water daily.