Dark Soy Sauce

The dark color and extra viscosity comes from the addition of caramel color (a product of cooked sugar). Some manufacturers also use a vacuum-dehydration process to concentrate the sauce. Not only does dark soy have a desirable, slightly bitter flavor, but its jet-black color enables it to be used as a coloring element in dishes like stir-fried noodles without adding too much soy flavor. See for the Malaysian Stir-fried Rice Noodles with Shrimp char kway teow. A drop will add a rich brown color to a soup, stew, or sauce. There is also one variation available—mushroom dark soy sauce—that is traditionally made by infusing dark soy sauce with straw mushrooms. Some manufacturers have switched to using the more savory and widely available Chinese black (shiitake) mushrooms for a more intense flavor.