P. L. Simmonds, The Commercial Products of the Vegetable Kingdom
“ The pods of the West India locust tree, Hymenæa courbaril, also supply a nutritious matter.That well known sauce, Soy, is made in some parts of the East, from a species of the Dolichos bean (Soja hispida) , which grows in China and Japan. In Java it is procured from the Phaseolus radiatus. The beans are boiled soft, with wheat or barley of equal quantities, and left for three months to ferment; salt and water are then added, when the liquor is pressed and strained. Good soy is agreeable when a few years old; the Japan soy is superior to the Chinese. ”
