Are Curds the Way? How Tofu is Made
From silken to extra-firm, plain to marinated, baked, and spiced, tofu has crept it’s way into Western palettes and become a household name, and in some cases staple. In the store the familiar white cubes come neatly packaged in a vacuum seal sometimes with water, and sometimes without. While the origin of curdled milk products, like cheese, is fairly well known and well-described among Americans, the origin of tofu seems much more obscure. How does a soybean go from being the bright green edamame we all know and love to the pale white block that is tofu? The answer is actually quite simple: through curdling and pressing, just like cheese.
Tofu starts with soybeans identical to the ones used in edamame. These soybeans are dried out fully, and then soaked in water for about 24 hours. The beans are then ground up finely and boiled with water to make soy milk. The soy milk is then heated and coagulants are added to begin the curdling process. Unlike cheese coagulants, which are composed of enzymes known as rennet, tofu coagulants are salt based and made from magnesium chloride, in the case of Japanese-style tofu, or gypsum, in the case of Chinese-style tofu. The coagulated soy milk is broken up into chunks so that it resembles scrambled eggs, and is then transported into rectangular molds lined with cheesecloth. These molds are pressed with weights to remove the excess water and increase the firmness of the final product. Once the extra water has been removed, the resulting blocks of tofu are cut, packaged and delivered to the grocery store in the form we all know and recognize.
Slight variations on the process result in different textures and firmnesses of tofu. Silken tofu, for instance, does not have it’s curds broken up and reformed in molds like other types of tofu. This results in a much smoother and softer texture than ordinary varieties. This smoothness makes silken tofu ideal for use in smoothies, desserts, or anything that requires the tofu to be blended into something else. However, the lack of firm structure and high water content means that silken tofu varieties often do not fare well in stir-fries, or when cooked as meat substitutes. For things like tofu stir-fry, scramble, or marinated strips, firm or extra firm tofu is ideal. It has been pressed long and hard enough that it contains much less water than it’s silken cousins, and has enough structure that it can withstand being tossed and flipped about on a griddle.
With this in mind, making silken tofu at home is a relatively simple endeavor that requires no specialized tools or equipment. All that you need is magnesium chloride coagulant, usually sold in packets as nigari, soy milk, and saucepan. You will want to make sure that the soy milk you choose is ONLY made from soybeans and water. The most common types of soy milk available often have sugar and carrageenan added to improve the flavor and texture for drinking. The presence of these added ingredients will affect the ability of the nigari to coagulate the milk effectively and therefore should be avoided if the intention is to make tofu.
To make silken tofu, simply heat the desired amount of soy milk in a saucepan over low heat, stirring slowly. When the soy milk reaches a temperature between 158 and 167 degrees, remove it from the heat and add a small amount of nigari. Stir the mixture immediately and continue stirring until a small amount of resistance develops. Finally, cover the pot and allow the mixture to set for 15 minutes. After the time is up, the soy milk will have fully curdled, and you’ll have perfect silken tofu ready that is ready to eat!
Currently, we have nigari packets and soy milk specially formulated for tofu-making, along with free instructional sheets, available here at Maido, if making your own tofu sounds like something you’d like to try. Tofu is an incredibly versatile food and the options that come with it are nearly endless. It is high in protein, and very low in carbohydrates, and fats, while still having a substantial mineral content, making it a perfect healthy addition to any diet style. Whether you want to eat it savory in a stir-fry, or sweet with fruit syrup as a dessert, tofu can surely accommodate whatever taste you have in mind.