The tangy sauce originated in ancient China as a brine of pickled fish or shellfish called "ke-tsiap." Neighboring countries adopted their own variations of "kechap" consisting of fish brine, herbs, and spices. In the late 1600s, English sailors visiting Malaysia and Singapore were so impressed with the sauce that they took samples home. English cooks attempted to duplicate the spicy sauce, but without access to some of the exotic Asian ingredients, they improvised with cucumbers, mushrooms, nuts, oysters, and other variants.