Yamashin is a well-known company for making white soy sauce in Japan. They have 200 years of history since 1802.
White soy sauce is known for being used in expensive restaurants like "Ryotei". Yamashin made it possible to be used in normal homes for everyone. Yamashin first started brewing soy sauces and mirin then they started moving to make white soy sauce "Shiro shoyu"
What is white soy sauce? What is different to the normal soy sauce?
White soy sauce is almost exclusively made from wheat and does not contain much soy. It is usually made from around 80-90% wheat. Chefs prefer white soy so it doesn't taint the colours of the ingredients. Also since wheat contains sugar, it contains Amami sweetness more compared to dark soy sauce.
White soy sauce was made in Aichi prefecture in Japan where Yamashin is. Kinzanji miso was famous from that area back then, and the juice in the barrel after making miso was really nice, and that's how people in that area started making white soy sauce.
White soy sauce was often used in expensive restaurants but Yamashin found the possibility of use in everyday meals, and the use for food all over the world.