Making tofu at home takes time and effort but is a rewarding experience. The flavor profile of homemade tofu is even milder than that of store-bought tofu. This recipe requires only a few ingredients, including:
Dried soybeans: use high-quality soybeans for this recipe. The soybeans will at first be used to make soy milk, which will be transformed into tofu.
Water.
Nigari, which is the preferred coagulant in this recipe, it contains magnesium chloride, which reacts with the protein in the soy milk. This causes the soy milk to curdle. Gypsum can also be used as a coagulant, but it will result in a less firm tofu. If you can’t find either one, two table spoons of lemon juice mixed with 79 ml of water can also be used.

What equipment do you need to make tofu from scratch?
High-powered blender, which will be used to blend the soaked soybeans into soy milk. It is also possible to use a normal blender. However, it might take longer. Blending should result in a completely smooth milk that does not contain any chunks.
Two large stockpots: the soy milk will be cooked in two phases, once with the pulp in it and once after straining. It is also possible to make this recipe if you have only one large stockpot. After cooking it with the pulp in it, strain the soy milk into a large bowl. Then, rinse out the stockpot and pour the strained milk back into the clean pot for the second phase. When choosing the right stockpot, make sure that there is a few centimeters of head space, as the soy milk gets foamy while cooking and can rapidly expand and boil over. A heavy bottom is also ideal, as it helps prevent the soy milk from sticking to the bottom of the pan and scorching.
Tofu mold, which will be used to shape the tofu.

Recipe
The soybeans have a soaking time of at least 8 hours. The preparation time is approximately 30 minutes, and the cooking time is 20 minutes.

Ingredients for soy milk:
175 grams of soybeans,
1,89 liters of water.

Ingredients tofu:
118 ml of water,
1,5 teaspoons of nigari.

Instructions:
Add the soybeans to a fine-mesh sieve and rinse thoroughly.
Transfer the soybeans to a large bowl and add enough cool water to cover by at least 5-8 centimeters. Cover the beans and let them soak at room temperature for at least 8 hours or overnight. The beans should be soft enough to split in half when gently squeezed.
Drain the beans, give them a good rinse, and add them to a blender. Add in approximately 850 ml of fresh water and blend until completely smooth.
Meanwhile, bring circa 950 ml of water to a gentle boil in a very large, heavy-bottomed stockpot or Dutch oven.

Making the soymilk
Pour the blended soybeans into the water that has already begun boiling. Add about 240 ml of additional water to the blender and blend to pick up any soybean remnants. Then pour this into the pot.
Heat the raw soy milk over medium-high heat. Carefully watch and stir regularly with a wooden spoon or rubber spatula. Stir and scrape along the bottom of the pot, as soy milk has a tendency to form a film there that can scorch.
As it approaches boiling, soy milk will start to foam and expand very rapidly. Be ready to turn off the heat and/or remove the pot from the burner immediately once it starts to expand. At this point, we are ready to move on to the next step.
Take a second stockpot and strain the soy milk using either a colander or fine mesh sieve lined with cheesecloth, muslin, or a nut milk bag. Allow the mixture to cool for several minutes.
When the mixture has cooled down enough for you to handle, wring out the soybean pulp to extract as much soy milk as possible. The pulp (also known as okara) can be saved and utilized in a variety of dishes.
Bring the soy milk back up to a boil, then reduce the heat and simmer for about 10–15 minutes. The longer the soy milk cooks, the more of the beany flavor will be removed. The soy milk is now done cooking.

Making the tofu
Turn the heat off and allow the soy milk to cool down for approximately 5 minutes. It has to cool to around 82 degrees Celsius.
In the meantime, prepare the nigari solution. Wisk the powdered nigari into water until desolved.
Prepare the tofu mold by lining it with a reusable cheesecloth, which has to be wet and thoroughly rung out first.
Pour 1/3 of the nigari solution into the soy milk and gently stir 3–4 times. The mixture should begin to curdle slightly.
Pour another 1/3 of the nigari on top, gently stir again, and then cover the mixture and set a timer for 2 minutes to let it coagulate.
Pour the remaining nigari solution on top of the soy milk and gently stir again. You should clearly see the tofu curds separating from the liquid. Avoid overstirring and breaking up the curds. If it isn’t curdling, reheat the mixture over low heat, and after a few minutes, you should see the separation.

Shaping the tofu
Once the curds have formed, they will be transferred to our prepared mold for shaping. It’s very helpful to remove some of the excess liquid first. You could use a fine-mesh sieve for this. Use it to press down the soy curds and isolate some of the liquid, which can then be removed.
After removing the extra liquid, the soybean curds can be ladled into your prepared tofu mold. Level the top out gently with a spatula or a spoon, and fold the overhanging cheesecloth neatly over the top and place the top on the mold.
Next, weigh the tofu down with a heavy object for about 30 minutes to yield a medium-firm block of tofu. You can add more weight and time for a firmer tofu or less for a softer tofu.
Once the tofu is done pressing, unwrap it from the cheesecloth and transfer it to a bowl of cold water. This will help it to firm up and will simultaneously remove any residual bitterness or sourness from the coagulant.

Sources:
https://sarahsvegankitchen.com/recipes/homemade-tofu/