Tamari soy sauce (aka tamari shoyu) is a rich, very dark soy sauce made with little to no wheat (this tamari is wheat free). Its flavor is salty, full of umami, and reminiscent of dark miso. It is more complex and potent than conventional basic soy sauce (as well as slightly thicker).
This tamari is traditionally slow-brewed over the course of 16-24 months (details below). Its flavor is the result of generations of tradition, knowledge, skills, and carefully cultivated strains of microorganisms coming together to produce extremely high quality soy sauce.
Soy sauces range across a continuum based on their wheat & soy content. Basic soy sauce lies in the middle of the scale. Robust tamari soy sauce is on one end (little to no wheat content and all soy) and delicate, almost clear white soy sauce is on the other (much higher wheat content than soy content).
How this Tamari is Brewed:
This tamari sauce has been traditionally slow-brewed using a process requiring tremendous expertise and patience.
In the late fall/early winter - milled, steamed soy beans are inoculated with koji - a special mold. This mold produces enzymes that break the beans down into simple sugars during a three-day incubation period.
At this point the resulting product is mixed with salt water to produce a mash (moromi) which is packed in cedar kegs (many two or three centuries old) for fermentation. It will age through two summers, until it is judged to be just right.
In the kegs the koji enzymes continue to work, and natural yeasts convert the simple sugars they produce into alcohols and esters. Other enzymes break proteins down into amino acids and bacteria produce lactic acid. Each of these elements (plus the work of various other local bacteria) combine to give this tamari its complex layers of sweet & savory flavors.
As with sourdough bread in the US, different areas of Japan possess wild yeasts and bacteria strains which give distinctive flavors to soy sauces. This tamari is produced in an area that has long been renowned for its soy sauce.
Once the mash is sufficiently aged, it is pressed to produce raw soy sauce. This sauce is allowed to settle for a month, then oils are skimmed off the surface and sediment is drawn off from the bottom. It is carefully heated to 80˚C/176˚F for an hour - killing the bacteria while preserving the enzymes and delicate flavor compounds. Then it’s finally bottled and ready for you to enjoy.