Liquid Soybeans

Though I reach for that penguin shaped bottle with the almost black liquid on a regular basis, I never really looked into the origin of shoyu… until now. In the 50th especially in the Tatsumoto household, the only shoyu on the table was Aloha Shoyu. No Kikkoman or other shoyu created in Japan, just local Aloha Shoyu. And to this day, I always stock a half-gallon of the reduced sodium variety of Aloha Shoyu specifically for marinades. The Origin of Shoyu Way back in China well before the modern calendar started during a Zhou Dynasty, there was a fermented fish sauce that also used soybeans to foster the fermentation process. Way back then, salt was a very valuable commodity, so these fermented salt-based sauces was a way to stretch this mineral. In fact, early Roman soldiers were paid their wages in salt hence the term we use to describe our wages – salary as the “sal” syllable refers to salt. Then sometime during the Han Dynasty, a sauce was created that primarily used soy paste instead the older fish-based sauces. The original fish-based sauces eventually made their way to Japan and when Buddhism was introduced from China along with the customary vegetarianism followed by many Buddhists, a pure soybean based fermented sauce took root in Japan. The Basic Shoyu Traditional shoyu usually takes several months to create. The soybeans are first soaked then boiled while wheat berries are roasted then crushed. Roughly equal parts of each are mixed to form a coarse grain then inoculated with a koji starter consisting of Aspergillus mold (the same mold breaks down starches in rice to start sake brewing). The three basic Aspergillus molds are Aspergillus oryzae and Aspergillus sojae which are the main workhorses to breakdown the soy proteins and Aspergillus tamarii which is primarily used to make tamari shoyu. Saccharomyces cerevisiae is also added (the yeast used to make wine) which creates alcohol and other flavor compounds as well as Bacillus bacteria (the bacteria that creates natto) and Lactobacillus (the bacteria that creates yogurt) which creates other flavor compounds and acids. Either a wet, salt brine or coarse salt is added to the cultured grain mixture and this then naturally ferments with amino acids from the protein reacting with sugars from the starches creating both flavor compounds as well as the characteristic dark color of shoyu – via the Maillard reaction for you chemistry geeks. After fermentation is complete, the mash is then pressed to separate the liquid from the solid, pasteurized and filtered. This newly fermented shoyu can then be bottled and sold, aged or infused with other flavor components to create other sub-categories of shoyu. Of course, you can always take a short cut and simply acid-hydrolyze the soy proteins, add caramel color to obtain the characteristic dark color and sugar as well as acids to create shoyu is about 3 days. However, this manufactured versus fermented shoyu usually doesn’t have any of the complex flavors in naturally fermented shoyu though it does have a longer shelf life. Though these chemically created shoyu don’t obviously state it on the label, my general rule of thumb is if the bottle is larger than your standard sized wine bottle or if it’s in a take-out packet, there’s a good chance it wasn’t naturally fermented.

Variations of Shoyu There are five main classifications of shoyu as determined by the Japan Agricultural Standards (JAS) and they are: Common or Koikuchi shoyu This accounts for about 80% of shoyu production and has a balance of salty, sweet, umami, acid and bitterness and is meant for table use and in cooking. Light Color or Usukuchi shoyu Accounts for almost 10% of shoyu production, it’s created with more salt to slow the fermentation process. Lighter in flavor and aroma as it’s meant to highlight the natural flavor of ingredients being cooked. Tamari shoyu Mainly produced in the Chubu region, it has a thicker consistency with more umami. Though usually a table shoyu for sashimi and sushi, it’s also used in grilled or boiled dishes. Refermented or Saishikomi shoyu Produced mainly in Yamaguchi prefecture, it’s called refermented shoyu as it’s a blend of various shoyu. Also called sweet shoyu with dense color, flavor and aroma, it’s mainly a table shoyu for sashimi, sushi or cold tofu. Extra Light Color or Shiro shoyu Originating in Aichi prefecture, this amber-colored shoyu has very subtle flavor but with a pronounced sweetness and is mainly used in soups or chawamushi custard. Of course, other than the five JAS classifications, you can find a wide range of shoyu whether it’s barrel aged, infused with vinegar and citrus (ponzu), smoked or traditionally fortified with konbu, katsuo-bushi and sugar. While I do partake in gourmet shoyu usually as a dip for sashimi or sushi, my usual shoyu application doesn’t involve gourmet or even naturally fermented shoyu. It simply involves reduced sodium Aloha Shoyu, brown sugar and an herb mixture. I first found the herb mixture at the Macys at Union Square while still attending graduate school which simply consisted of rosemary, sage, lemon thyme, garlic powder and onion powder. I never found the product again during subsequent visits to the Bay Area so I simply pour a heaping tablespoon of dried, crushed rosemary in bowl then add slightly less rubbed sage, less lemon thyme, less garlic powder and finally less onion powder (diminishing piles of each). A heaping tablespoon of this mixture is then mixed with about ½ cup of reduced sodium Aloha Shoyu and about ½ cup of brown sugar. I then marinate either pork tenderloin or pork sirloin for 24 hours then smoke, pan fry or grill on medium-low heat (to prevent the brown sugar from burning). I’ve given containers of the herb mixture to friends labeling it as the “Gochiso Gourmet’s Porky Herbs.”

Shoyu Service Do you have your shoyu dispensing container sitting either on a folded paper towel or on one of those small, shallow ceramic plates used to dip your sushi into? I’m sure everyone has experienced shoyu leakage from that glass, ceramic or plastic shoyu pouring vessel where the shoyu dribble dries to a sticky, salty mess on the side of the vessel eventually creating that ring of sticky mess under the vessel. Well, I think I found the perfect serving vessel I dub “The Penguin.” The soft sided vessel with a single exit is squeezed to release the shoyu then a quick release causes the vacuum produced by squeezing to suck that last drop of shoyu back into the container. No dribble, no mess.