Chinese families left tofu at graves because ghosts had no jaws
In Chinese tradition, relatives brought tofu to the graves of the dead. Ghosts, it was said, had long ago lost their chins and jaws, so only something this soft was fit for them to eat. The food itself had a humbler practical problem: before refrigeration, fresh tofu went bad within a day in warm weather.
Making tofu is much like making cheese. Soybeans are soaked, ground in water, filtered and boiled into soy milk, then a coagulant is stirred in so the proteins clump into curds, which are pressed into blocks from silken to extra firm. Heating unfolds the soy proteins, whose negative charges normally keep them apart; metal ions from the coagulant neutralise those charges so the proteins bind together. Gypsum, quarried and used unrefined, is the cheapest and most traditional choice in China. Japan favours nigari, a magnesium-rich powder left when salt is removed from evaporated seawater. Silken tofu often sets with glucono delta-lactone, which slowly turns acidic and lets it form smoothly right in its tub without pressing.
Legend credits Liu An, a Han dynasty prince who lived from 179 to 122 BC, though inventions were often pinned on famous figures. A stone mural found in an Eastern Han tomb in 1960 supports an early origin. Rival theories say soy slurry curdled by accident when mixed with impure sea salt, or that Chinese cooks copied Mongolian milk curdling. Either way, tofu only became popular in China under the Song dynasty, from 960.
Buddhism carried it abroad as a vegetarian protein. Zen monks brought it to Japan, where it appears as an offering at Nara's Kasuga Shrine in 1183, and a 1782 book offered a hundred tofu recipes. A Javanese inscription from 902 lists bean curd at a royal feast. In English the word first appears as towfu in a 1770 letter from the merchant James Flint to Benjamin Franklin, who described it to a friend as cheese from China.
The first American tofu company opened in 1878, and in 1908 Li Yuying founded what was apparently the world's first soy dairy, in France. Most Westerners met it only after William Shurtleff and Akiko Aoyagi published The Book of Tofu in 1975. Soybeans rank among the most land-efficient, lowest-emission protein sources of any food.
Source: Tofu
