Black Soy Sauce – Siew Dam
by Kasma Loha-unchit
See Also: Palm Sugar.
This is a rich and thick sauce, made by fermenting soy sauce with sugar or molasses. Black in color and thick like a light syrup in its consistency, it has a delightful flavor and is used as much to add sweetness as saltiness to rice and noodle dishes, soups and stews and various stir-fries. Although it could be considered a sweetener, it belongs equally in the category with salty ingredients. Do not mistake this soy sauce with other dark Chinese and Japanese soy sauces that aren't sweetened.
To assure that you are getting the right kind, look for a bottle that identifies the product as coming from Thailand. There are a few different brands, but the most commonly carried in Asian markets in the West is made by the Kwong Hung Seng company of Thailand and has a dragonfly on the label. Make sure the label says "black soy," as the "Dragon Fly" brand makes three kinds of soy sauces ("sweet soy sauce" and "thin soy sauce" are the others) with almost identical labels, save for the name of the sauce. Although it is sweet, it is not the same as "sweet soy." The latter, used primarily for particular sweet snacks, is even sweeter and is thick like ketchup. Black soy sauce does not need to be refrigerated after opening. and keeps indefinitely in a cool place in your cupboard.
If you are unable to find black soy sauce, substitute with a mixture of equal parts dark soy sauce and either palm sugar or blackstrap molasses.
Our Ingredients Index contains links to many more Thai ingredients.