Silken tofu, unlike regular tofu, does not entail pressing the whey out during the tofu making process. Rather, the soy milk is solidified in its final container. The curds and whey never separate, resulting in the velvety soft texture of silken tofu, called kinugoshi-dofu (silk-strained tofu) in Japanese.
This tofu’s rich and fatty flavor derives from the fact that it is made from soy milk that’s thicker than that used for block tofu. Think of the difference between ice creams made from milk versus those made from cream. Each has its own merits, but the flavors and textures are different. Silken tofu reveals its elegant creaminess when eaten slightly chilled with a few simple garnishes, such as for hiya yakko, a Japanese classic.
The trick to making silken tofu is to prevent curds and whey from forming, which happens if the soy milk gets too hot. Commercial producers use a carbohydrate called glucono delta-lactone, which is not widely available to home cooks. However, some small-scale tofu producers and chefs steam cold soy milk with nigari until it’s just set, then serve it chilled in its container.
I tried the slow and gentle steaming technique with my favorite coagulants and found that nigari, both liquid and refined crystals, and Epsom salts produce slightly weepy tofu that’s cloudy at the bottom when the soy milk is cooked in large quantities. However, gypsum produces a gorgeous, silky texture that molds well with no weepiness, even when I steam the entire quantity of soy milk in a glass loaf pan; it is the best overall coagulant for this type of tofu. The artisanal tofu makers I met in Japan also use gypsum for their silken tofu.
Feel free to steam as little soy milk as 1 cup at a time. Just use a third of the coagulant and water. Remember to make the soy milk in advance and refrigerate it until you need it. It is fine if the soy milk is cold, slightly chilled, or at room temperature; it should not be warm or hot. That is, don’t make the soy milk and then move right into this recipe. If you do, the moment you add the coagulant to the warm or hot soy milk, it will separate into curds and whey.
- 3 cups Rich Soy Milk chilled or at room temperature
- 1 1/2 teaspoons packed gypsum
- 2 teaspoons water, filtered or spring preferred
1. Choose a large mold or several small molds to steam the soy milk in. Glass or ceramic containers with straight, smooth inner walls work best for unmolding; make sure the mold fits in your steamer tray. If you want easy cooking and storage, and don’t mind if the tofu is served in imperfect shapes and irregular sizes, select a vessel such as a glass loaf pan. For individual servings, use 3- or 4-ounce ramekins. There is no need to oil the mold for silken tofu.
2. Get a pot of water boiling for steaming. Stir together the gypsum and water to dissolve.
3. When the water comes to a rolling boil, lower the heat to steady the flow of steam. Give the soy milk a stir and if it is not totally smooth, pass it through a coarse-mesh strainer. Now, combine the soy milk and coagulant liquid, stirring to blend well. Pour into the molds to a depth between 1 and 2 1/2 inches.
4. Place the molds in the steamer tray and position the lid slightly ajar to minimize the amount of condensation dripping down. Gently steam the soy milk until the tofu has set. The amount of time required depends on the quantity of soy milk and the size of the mold. In general, it takes about 6 minutes to set 1 inch of soy milk. The tofu is done if it jiggles when you shake the mold; if you pick up the mold and slightly tilt it, the tofu may slide around. A toothpick inserted into the center will leave a tiny visible hole on the surface. You may steam the tofu for a few more minutes because the gentle heat will not harm the outcome.
5. Detach the steamer tray and cool for a few minutes before removing the molds. Cool the molds completely at room temperature. To unmold the tofu with ease, cover and chill in the refrigerator for at least 4 hours. You can keep the tofu refrigerated for up to 3 days. Let it sit at room temperature for about 15 minutes, then run a knife around the edge (just like a cake) and invert it onto a flat surface. The water that releases as the unmolded tofu sits is the whey.
Variation: Citrus-Scented Silken Tofu
When I visited Tokyo to do research for this book, Japanese food expert and author Elizabeth Andoh took me to visit Toshio and Kyoko Kanemoto, the proprietors of her neighborhood tofu shop, Nitto Tofu. Among the couple’s superb offerings was an amazing yuzu-flavored silken tofu. Once I tasted it, I had to recreate it. It turned out to be easy.
Choose an aromatic citrus, such as Meyer lemon, lime, orange, or Buddha’s hand. Grate just the skin, using a Japanese ginger grater, if possible, to obtain the finest texture. For every cup of rich soy milk, use 1/2 teaspoon grated zest (the amount from an average lemon). Stir in the zest before adding the gypsum coagulant. Then steam as directed above.
The citrus oils are spotlighted when the tofu is simply presented. Tester Makiko Tsuzuki enjoyed it as small chunks with a light drizzle of soy sauce. I also like to feature it in the creamy edamame soup.