How we tested

Tofu dates back 2000 years to China’s Han dynasty and has long been a staple in Asian cooking and a favorite among vegetarians. And its popularity in the United States is on the rise: Americans spent $274 million on this mild-tasting soybean product in 2013, and sales are trending up. To find the best product for the home cook, we set our sights on firm tofu because it’s the type we call for most often, as it’s more versatile than silken or extra-firm tofu. We found five nationally available, American-made products, priced from $0.08 to $0.40 per ounce, and tasted each plain, coated with cornstarch and fried, and chopped and stir-fried in a filling for Thai basil lettuce wraps. A panel of tasters rated each sample on texture, flavor, and overall appeal.

Happily, our tasters liked the flavor of every tofu. Plain and in our recipes, the samples tasted “neutral” and “clean,” with subtle “sweet,” “nutty” notes. Regarding texture, most were exactly what we’ve come to expect in tofu: firm enough to hold their shape for cooking and frying yet still pleasantly soft and tender. But there was one outlier. Cut into cubes and tasted plain, this tofu was so dry, firm, and compact that our tasters compared it to rubber erasers. The lower moisture level meant that the cornstarch couldn’t completely gelatinize, so the coating turned pasty and sludgy when fried. And when we chopped this tofu in a food processor, it broke into irregular shards instead of forming small, tender crumbles.

Why was one tofu so different from the others? The answer lies in how tofu is made. All firm and extra-firm tofu begins essentially the same way: Dried soybeans are soaked and ground to create soy milk, and that liquid is separated from the soybean pulp—at this point, it’s actually a lot like making cheese. A salt- or acid-based coagulant is added to make the milk separate into solid curds and liquid whey. The curds are then placed in molds, drained, and pressed to squeeze out moisture and make them more compact. It’s the pressing that plays the biggest role in determining texture; firmer tofu is pressed more.

When we asked manufacturers for more detailed information on how their tofu is made, we found more similarities than differences. Most of the tofus in our lineup are made with soybeans grown in North America. They use a variety of coagulants—including nigari (a byproduct of extracting salt from seawater), calcium sulfate and magnesium chloride (two forms of salt), and an acid-forming substance called glucono delta lactone—and our tasting panel didn’t detect any meaningful differences in flavor. Manufacturers cited a range of processing temperatures (from 100 to 200 degrees), pressing times (from 20 to 30 minutes), and pasteurization temperatures (from 150 to 167 degrees). But again, that information couldn’t explain our preferences.

The difference turned out to be simple: protein content. Our four recommended tofus contain 7 or 8 grams of protein per 85-gram serving (about 1/3 cup). The lowest-ranked product contains twice that amount—14 grams. Soy is the only source of protein in tofu, so this dramatic difference in overall protein content indicates that this product contains much more soybean curd per serving—no wonder it was so much denser than the rest. A handful of tasters enjoyed its firmness, but the majority thought that it seemed like an entirely different product.

Ultimately, any of the top four products in our lineup will yield successful results in the kitchen. But Nasoya Organic Firm Tofu ($2.99 for 14 ounces) was our favorite. Its light, clean flavor earned praise in every tasting, and it struck just the right balance between firmness and tenderness. We think both tofu skeptics and aficionados will approve.

Methodology

Panels of 21 tasters sampled five nationally available firm tofus in three blind taste tests. After cutting and draining the tofu and patting it dry, we served each plain, coated with cornstarch and fried, and chopped and stir-fried in a filling for Thai basil lettuce wraps. Tasters evaluated each on its flavor, texture, and overall appeal. Scores were averaged, and the products appear below in order of preference. Details on production were obtained from manufacturers. Nutritional information and ingredients were taken from product packaging and, where necessary, converted to a standard serving of 85 grams (roughly 1/3 cup). Prices were paid in Boston-area supermarkets and online.