Tofu (also known as bean curd and dofu and dau foo, its Japanese and Cantonese names, respectively) is made by coagulating fresh soy milk with a calcium compound until it curdles. The resulting curds are pressed with weights in cloth-lined wooden trays. Custard-like silken tofu, which contains the most moisture, has been pressed the shortest amount of time, while firm tofu, which has a denser, mozzarella-like texture and contains less moisture, has been pressed the longest. Though originally from China, the ingredient has been a staple in Malay Archipelago cooking for thousands of years. Local cooks adore the ability of deep-fried firm tofu to absorb and mingle with saucy curries and intense seasonings.

Before firm tofu is added to an Indonesian, Malaysian, or Singaporean dish, it’s almost always sautéed or deep-fried, which deepens its taste and makes its surface beautifully crisp and golden; un-fried tofu is considered too mushy and characterless to use in dishes. Firm tofu—as opposed to “silken” or “soft” tofu—is essential for making deep-fried tofu. Watery silken tofu can react dangerously with hot grease, causing it to bubble over or even catch fire. Firm tofu, conversely, easily deep-fries to a wonderfully porous crispness. Before deep-frying firm tofu, be sure to pat it dry well—it will splatter aggressively when added to the hot oil otherwise. Also, be certain to fry it only to the point that its surface is just golden; over-fried tofu is dry, tough, and bitter tasting.

Firm or extra-firm tofu is sold in water-filled (the water keeps the tofu from drying out) sealed plastic containers holding from one large rectangular block of tofu to four smaller square-shaped ones. Tofu is also occasionally available in open containers and buckets in Asian markets or greengrocers. Even though it’s cheaper than tofu in sealed containers, don’t buy it—it’s highly prone to bacterial contamination. I purchase all my tofu from Chinese and Southeast Asian markets near my New York home, which carry a broad selection of excellent-tasting tofus manufactured by small local tofu companies. Roam through the tofu section of your nearest Asian market to familiarize yourself with the locally made brands available in your area. I avoid tofu from Japanese companies (such as Azumaya), as well as tofu sold in health-food stores (such as Nasoya). Even though these packaged tofus may be labeled “firm” or “extra-firm,” they tend to have a high moisture content, which means the tofu will not fry well.

Tofu is highly perishable and, like fish or chicken, must stay refrigerated. When selecting tofu, check the expiration date on the label. Most brands of tofu manufactured by Chinese companies allow you to see the tofu inside the container through a clear, see-through portion of the label. Choose containers whose tofu is brightly white with no signs of yellowing. The water the tofu is immersed in should be clear, not cloudy (a sign of spoilage). Store sealed containers of tofu in the coolest part of your refrigerator (toward the rear) for up to four days, depending on the tofu’s freshness. Once you open the container, smell the water—it should give off a clean, nondescript aroma, not a swampy or sour odor. Also, test a sliver of tofu—it should taste bland and vaguely sweet, not at all sour or “off.” Transfer any tofu that you don’t use to a nonreactive bowl filled with fresh water; it will keep refrigerated and covered with plastic wrap for two to three days. Tofu that you’ve deep-fried and haven’t used in a recipe will keep refrigerated sealed in plastic wrap for up to four days; you can add it later to curries and stir-fries.