About 1,500 years ago, in the mountains of northern China, you might have found bamboo mats lined with slabs of tofu, resting in the snow overnight. Once frozen solid, “the structure and basic character of the tofu underwent a radical transformation,” William Shurtleff and Akiko Aoyagi wrote in “The Book of Tofu” (1975).
Like the best of us, tofu is made up of mostly water. When that water turns to ice, then melts, it leaves behind what Mr. Shurtleff and Ms. Aoyagi called “a lacy but firm network.” This more compact, spongy form of tofu, it turns out, is especially great at becoming truly and unapologetically crisp — crunchy, even — in the oven.
Freezing is one of the best ways to get the crispiest tofu without deep-frying. In this recipe, you then simply roast it: Heat the oven with a sheet pan inside, so that the pan is dancing-hot before you even add the oil. Then, carefully place frozen and thawed tofu slabs onto the hot, oiled pan — you should hear a sizzle — and cook until deliriously crisp.
There are many reasons to freeze your tofu. Maybe you just got back from the store and don’t know what to cook with that block you just bought. Or maybe you appreciate the meaty texture that freezing creates, strengthening the delicate but resilient sponge.
The chef Brooks Headley of Superiority Burger said he likes to both freeze and thaw tofu directly in a flavorful brine, so that once it thaws, the brine can penetrate the tofu. It’s up to the cook to decide what to do with the moisture left inside thawed tofu: To press or not to press? In the “Superiority Burger Cookbook,” Mr. Headley presses marinated tofu “to remove some of the moisture” before breading and frying for his tofu-fried tofu sandwich.
But beware: Squeeze out too much liquid and you’ll end up with dry crackers, which are delicious in their own way but not as fresh-tasting as tofu that is cacophonously crunchy at the edges, with juicy, tender centers — what Corinne Trang, the author of “Twist on Tofu” (2022), calls balance. “It’s that yin-yang thing,” she said, though she pointed out that, “in ancient times, if we had the technology we have today, like refrigeration, we probably would not freeze a delicate product like tofu.”
Many tofu experts like Ms. Trang and Andrea Nguyen, who wrote the cookbook “Asian Tofu” (2012) and this primer on tofu, believe in celebrating the product for what it is. “Why are people wanting to take something tender and luscious and turn it into a chewy sponge?” Ms. Nguyen said.
“When I’ve frozen tofu, it’s because I have an orphaned block and am leaving town, so I need to preserve it.”
Aside from helping tofu keep, freezing firm or extra-firm tofu conveniently removes enough moisture so that it can properly roast in the oven rather than steam. And, perhaps best of all, it also concentrates and accentuates the comforting taste of soybeans: gently sweet with a quiet balm of umami, and, when caramelized at the edges, a little nutty like popcorn.
The tofu’s true flavor shines when eaten on its own, with a generous sprinkle of salt. Or, served on a large platter with your favorite dipping sauce or stuffed into a sandwich? No one would complain.