making soy milk in the previous post. The yield from that recipe (about 8 cups) will provide enough soy milk for today's tofu recipe.
Tofu making is similar to cheese making in that you'll be separating the milk into curds and whey and for that you'll need a coagulant. I used food grade gypsum (calcium sulfate) available from home brewing suppliers or sometimes Asian grocery stores. I found gypsum at Eats in Blacksburg for .87/2 oz. That 2 ounces will make many batches of tofu. Other coagulants include nigari (magnesium chloride) and Epsom salts (magnesium sulfate). Andrea Nguyen recommends nigari and gypsum as her 1st and 2nd choices.
To begin, make a batch of soy milk but after the final cooking do not cool it down as you would for future drinking or cooking. Tofu making works best with a freshly made and still warm batch of milk. Bring the milk back to a gentle simmer for 5 minutes, stirring frequently.
While the milk is heating combine 1 1/2 packed teaspoons of the coagulant of your choice with 1/2 cup of water. Whisk well to dissolve. You're going to add this coagulant to the milk in thirds so remember to whisk it each time before adding since the particulates have a tendency to settle out of the water.
Also, prepare and arrange your mold(s). You don't need a special tofu mold for this. The first time I used a footed colander lined with regular cheese cloth that sat in my kitchen sink. This time I used little foil loaf pans that I perforated and lined with cheese cloth. Perforate only the bottom pan. You'll sit a second solid pan on top as the pressing plate.
After the soy milk heats, take it off the heat and allow it to cool down to 170F, stirring frequently to prevent a skin from forming. If you're not using a thermometer give it about 3 minutes to get in the neighborhood of 170F.
Stir the pot vigorously in a Z motion to agitate the liquid so the coagulant will mix in well. Pour in 1/3 of the prepared coagulant. Stop the spatula upright in the center of the pot to slow down the movement. When the milk stops moving pull the spatula straight up out of the pot.
Using a spoon, sprinkle another third of the coagulant on top of the milk. Cover the pot and wait 6 minutes. If you are using Nigari cover the pot and wait 3 minutes.
Stir up the coagulant again and sprinkle the remaining third on the surface of the milk. Using the tip of the spatula stir the top 1/2" layer of the soy milk for about 20 seconds, paying attention to the edge as well. The milk will be curdling and you'll be able to feel it thickening as you move the spatula over the curds. If you look closely you may be able to see the milk begin to separate into curds and whey. Cover the pot and wait 6 more minutes (3 for Nigari), then stir the surface again for 20 more seconds.
I placed my molds in a sieve over a bowl to catch the whey as I was filling them. Use a slotted spoon to gently lift the tofu curds out of the pot, disturbing them as little as possible, and lay them into the cheesecloth-lined mold.
Fold the cheesecloth evenly and smoothly over the top of the curds. Here you can see that I placed the molds on a cooling rack on the lipped baking sheet.
When all the curds are in the molds, strain the remaining whey from the pot and into a jar for later use. Some folks who make tofu regularly use the whey to coagulate future batches of milk. I use it in cooking. The whey contains about 9% of the original protein in the beans. If you use the lees from milk-making and the whey from tofu-making you'll have recaptured about 25% of the original bean proteins that otherwise would have gone in the trash.
Place the solid bottom loaf pans on top of each mold. If you're using a colander place a plate on top of the wrapped curds. I placed another baking sheet on top of the loaf molds.
Here you can see that quite a bit of whey gets pressed out of the curds during this step. I captured about 2 cups worth here for a total of 4 cups between the pot and the press.
Allow the tofu to press anywhere from 20 minutes to a couple of hours depending on how firm you prefer yours. I like a good firm tofu for most cooking purposes so I go the full 2 hours. At any point during the pressing feel free to unwrap a mold and check the firmness by pressing on the tofu with your fingertip.
When the tofu has reached your desired level of firmness, carefully lift the blocks by the cheesecloth out of the molds and unwrap.
You can use the tofu immediately but it will develop more flavor if allowed to rest for 2 hours before using. To store it, place it in the fridge in its tub of water. Change the water every other day. The tofu will hold for up to 1 week.
If you've never had fresh tofu before (and face it, how many of us have a mom & pop tofu shop down the street), you'll be amazed at the texture and flavor it really has.
I've also learned that tofu doesn't have to be that plain white block. Starting with my next batch I'll be exploring the addition of herbs, vegetables, fruits, and other sweet and savory flavors, as well as smoking and fermenting.