The Complete Handbook of Tofu

Chapter 1: Understanding Tofu

What Tofu Actually Is

Tofu is a soy-based food product made by coagulating the protein and oil that have been extracted from ground, cooked soybeans into a solid block. The process is a controlled version of something you might remember from a bad science fair experiment: you take a liquid that is full of suspended particles, change its chemistry slightly, and those particles clump together into a solid mass. In the case of tofu, the liquid is soy milk (the water-soluble protein and fat from soybeans) and the chemistry change is the addition of a coagulant, typically a calcium or magnesium salt. The result is a white, high-moisture curd that can be pressed and shaped into a huge range of textures.

To make this more concrete, picture a 500-gram block of firm tofu you might buy at a grocery store. That block contains roughly 60 to 70 percent water, 10 to 15 percent protein, 5 to 8 percent fat, and the rest is carbohydrate and ash. If you let that same block sit in a dry container in your refrigerator overnight, it will lose water through surface evaporation. The next day it will be slightly firmer and noticeably less slick on the outside. That water is not a contaminant; it is the medium that carries the flavor, and its exact amount is the single largest factor that determines how the tofu behaves in a pan, a fryer, or a blender. The fundamental lesson of this chapter,