Sempio has mastered the art of soy sauce. They have spent 70+ years brewing Soy Sauce in the traditional way. This 501 Soy Sauce is their flagship product. It's a super-premium grade soy sauce, with a Total Nitrogen value of 1.5 (details below). A high TN value indicates a high amount of soybean protein, which translates to deep, rich flavor. Sempio's 501 Soy Sauce has become the go-to soy sauce for Korea.