While true tamari or shoyu is an aged product, most of the commercial soy sauce sold in the United States is a nonfermented synthetic product made from defatted soybean meal and grains mixed with chemicals. Real aged tamari or shoyu has a different flavor than commercial, synthetic soy sauce. In Japan, synthetic soy sauce is not recognized by the government, which allows five different types of soy sauce to be labeled as shoyu. Among the synthetic brands, reduced-sodium soy sauce is available.