Many refer to shoyu pronounced (show-you) as soja or Tamari. The earliest known reference to soy sauce in English was by the Englishman John Locke in 1679; he referred to it as “Saio.” In 1688 another Englishman, made the second reference to soy sauce, calling it “soy,” a name which stuck and became the most popular English term for over 230 years.

In the 1920s a very significant development took place in soy sauce manufacture, that took 60 years to be reflected in the popular terminology of the product; soy sauce started to be manufactured by a completely new process, using quick acid hydrolysis instead of the traditional slow fermentation method using enzyme hydrolysis.

Both products were called “soy sauce” although scientists and microbiologists often differentiated the two products by calling the new product “HVP (hydrolyzed vegetable protein) soy sauce,” “chemical soy sauce,” or “nonfermented soy sauce,” and the traditional product “fermented soy sauce.” However the general public was almost entirely unaware of this crucial distinction, even though specialists in the field generally agreed that the traditional fermented product was of superior quality.

The first person to try to make a change in the common or usual names of the various soy sauces to reflect their differences was the macrobiotic teacher George Ohsawa. He chose to use the term “tamari” to refer to the traditional, naturally fermented Japanese-style shoyu, which he worked to introduced into the West. Ohsawa made a mistake, however, in using the term “tamari” to make his distinction, since “tamari” also referred to a type of Japanese shoyu containing little or no wheat.

Starting in 1975 Shurtleff and Aoyagi began a mini-campaign to have all Japanese-style soy sauce called “shoyu” (to distinguish it clearly from both chemical soy sauce and Chinese soy sauce), to have the term “tamari-shoyu” or “tamari” used, as in Japan, to refer only to shoyu containing little or no wheat, and to have the product that Ohsawa and the macrobiotics called “tamari” be renamed “natural shoyu.”

Below is a homemade shoyu sauce, it is a process of adding flavour to shoyu by using kombu and bonito shavings and other ingredients.