How is Sengmyongmul Soy Sauce fermented differently from others?

Unlike many soy sauces fermented in outdoor fermentation tanks, 100% fermented Sengmyongmul Soy Sauce is made using natural bedrock water from 200 meters underground.

It undergoes natural fermentation for over six months in Korea’s first underground tunnel-aging facility, where classical music is played to help create a harmonious environment for fermentation.