There's nothing like fresh, handmade Japanese "silken" tofu (called kinugoshi in Japanese). Coaxed from just soybeans, water, and nigari, a coagulant derived from seawater, it's a quintessential expression of Japanese cuisine -- the idea of finessing something so sublime from a few simple elements. I first tasted the real deal at the workshop of a traditional tofu maker in Kyoto I visited one morning before sunrise. With a lovely custard-like texture, delicate natural sweetness and seductive fresh soybean flavor, their tofu had as much to do with the stuff sold in supermarkets as a beautiful farmstead ricotta does with a tub of Polly-O.
Here in New York, my friends at En Japanese Brasserie have made fresh tofu a centerpiece of their menu since the restaurant opened. It is absolutely wonderful tofu, and has gained a legion of devoted fans. Many customers have asked Chef Yasuhiro Honma how to make tofu, so now En runs occasional tofu-making demonstrations at the restaurant, which I help moderate. The latest one was yesterday.
You need soymilk and nigari to make silken tofu. You can produce soymilk from scratch, but a good ready made soymilk will work fine, too. Okay, so what's "good soymilk?" Soy milk is not the stuff you see in health food stores or supermarkets. Those products are watered down and loaded with (albeit natural) additives, flavors, salt and sometimes sweeteners. Even "unsweetened" commercial so-called soymilk doesn't cut it (read the label). You need real, fresh soymilk, made from two ingredients: soybeans and water. You can find said soymilk at Japanese and Asian food markets. Like cow's milk, it comes in half-gallon jugs and has an expiration date.
Nigari is magnesium chloride extracted from sea water (the salt is removed and water evaporated). It acts just like rennet does with animal milk in cheesemaking -- it coagulates the milk to produce curds and whey. You can also buy it in Japanese markets.
Now, there are two overall kinds of Japanese tofu: momen, a firmer tofu, and kinugoshi. Producing momen is a lot like making cheese -- the nigari breaks the soy milk down in to curds and whey, and you press the whey to form tofu blocks. With kinugoshi, though, you first thicken the soymilk by boiling off some of its water, then carefully add nigari in a such a way that it doesn't separate the soymilk. It you do this right, the soymilk remarkably coagulates into silken tofu. If you screw it up, it doesn't. You'll know right away.
You'll need: 2 quarts soy milk, 1 tablespoon liquid nigari, a wooden spatula and a square container (square is important -- Chef Honma calls for a 7 by 7 by 7 inch container).
Okay, here's how Chef Honma explained it:
Heat 2 quarts of soy milk over medium heat. Cook the soy milk until it's reduced by 80%. Now bring it to a temperature of 135 degrees Fahrenheit (use a kitchen thermometer).
Remove from heat and pour the soy milk into the square container. Now, pour the tablespoon of nigari into the soy milk all at once. Using the wooden spatula, stir with a back and forth motion a few times to mix well. Then stop the spatula upright in the center of the container and hold it there for a couple of seconds to halt the motion of the soy milk. Pull out the spatula, cover the container with plastic wrap and let it sit for 15 minutes.
The trick is in adding the nigari. If you stir too vigorously, you'll break the soy milk into whey and curds. You want the nigari to just combine with the soy milk, then halt the liquid from moving inside the container, which is why you stop the spatula in the center, which interrupts the movement. Also, a square container prevents the soy milk from swirling too much.
Okay, once you unwrap the container, if everything worked... you'll have tofu! Scoop out the tofu and eat it fresh and amazing, accented with a little soy sauce and ginger, or whatever you prefer. To can also cook with it -- just wrap the tofu in cheesecloth, place in a bamboo basket and store it for a few hours in the fridge so it releases water and firms up, just like in the photo above. Then go to town.
Let me know if you try making tofu -- how did it work out?
UPDATE 3/18: I spoke with Chef Honma some more and he says the temperature of the soy milk could even be hotter, between 140 and 160 degrees F. You'll have to experiment which temp works best with the nigari you've bought!