Calories in Soy milk, unsweetened, plain

What makes soy milk so powerful?

Soy milk's production is deceptively simple—soak soybeans, grind with water, strain—yet the chemistry behind its flavor is anything but. The characteristic "beany" taste that many find off-putting is caused by lipoxygenase enzymes native to the soybean. When the bean's cells are ruptured during grinding, these enzymes rapidly oxidize polyunsaturated fatty acids into volatile compounds called aldehydes, particularly hexanal, which humans detect at extremely low concentrations. This is the same class of compounds responsible for the smell of cut grass and old cardboard. Industrial producers combat this by either heating the slurry rapidly enough to denature lipoxygenase before it can act, or by using a "hot grind" method above 80°C. The irony is that lipoxygenase exists in the soybean not for flavor but as part of the plant's defense system, generating signaling molecules when tissues are damaged by pests. Soy milk itself traces back to China, where written references appear as early as the Han Dynasty, though the modern industrial process was refined in the 20th century.