How is Soy Sauce Made?

Process of Making Soy Sauce

Soy sauce is an indispensable part of our Bothell sushi restaurant. Every sushi fan knows the value of having a carefully mixed bowl of soy sauce and wasabi to dip their favorite rolls and nigiri into. But how is soy sauce made, exactly? Indeed, this classic brown fluid has a long way to go from the factory to your table, and it starts with this:

  • First, the soy sauce manufacturer soaks and steams a batch of soybeans, then mixes them with roasted grains of wheat.
  • Next, they cultivate koji mold on the mixture. This mold breaks down the protein in the soy and the carbohydrates in the wheat into a substance that the Japanese call shoyu koji.
  • About three days later, the shoyu koji is mixed with salt and water to ferment and age.
  • After a few months of fermentation, the shoyu koji turns into a thick mash. This mash is then pressed and strained through cloth filters to remove the fluid. This is what they call the “raw” soy sauce.
  • This raw soy sauce is cooked, to pasteurize the mixture and end the chemical reactions. This stabilizes the soy sauce so it can be bottled, served, and enjoyed!

Every soy sauce probably has their own secret way of making their signature soy sauce, but know that soy sauce is a great way to add flavor to your dish!