Those of us who love sushi probably believe we know all there is to know about soy sauce. As in simply choosing regular or low salt. Probably Kikkoman. Then we likely absently blending it with wasabe paste so we can dunk those precious pieces of raw fish and get a rush of salt and heat.
The problem is that most of us have never actually been exposed to true artisan soy sauce, made using traditional methods of extended fermentation instead of by machine and chemicals, and having only three ingredients: soybeans, wheat, and salt. Japanese soy sauces, called shoyu in Japanese, that have been slowly fermented for months, often in cedar casks, have an altogether different flavor and texture than the synthetic ones we in the U.S. tend to experience at the neighborhood sushi bar or off a grocery store shelf. They're also different from Chinese soy sauce, which, according to Shizuo Tsuji in the classic Japanese Cooking: A Simple Art, is very salty and has a dense flavor. Japanese soy sauces, he explains, have a relatively bright taste and aroma, and tend to be sweeter and less salty since they use far more wheat. They're also thinner in texture and clearer in color than Chinese-style sauces.
And those synthetic soy sauces? First, the manufacturing process cuts the natural brewing time of four to six months to develop flavor down to three to four days. And, instead of natural ingredients, you get hydrolized vegetable protein and hydrocholoric acid to get the chemical reaction going. Plus caramel and corn syrup is added for coloring and flavor. The result is a thick, black sauce often sold under a Chinese-sounding name. So, yes, check the label before you toss a bottle into your shopping cart next time. You'd be surprised. (As a side note, Kikkoman's soy sauces are made with the three traditional ingredients and is, according to author Tsuji, quite dependable, with the correct flavor and quality for cooking Japanese dishes--compared with Chinese type soy sauces or the chemical versions.)
Years ago, my friend Mineko Moreno, who teaches Japanese cooking locally, got me hooked on traditional soy sauces. She explained that these are sauces intended for dipping, not cooking--much like high quality olive oil. You want to experience the flavors of the soy sauce, not bury them in a Chinese stir fry or soup or other cooking preparation.
"I always tell my students that soy sauces like these should be used where the true taste of the soy sauce shines," she told me. On a tour of Nijiya Market, she pointed out several and I have been enjoying one made by Chiba Shoyu called Shimousa Shoyu.
Usually soy sauces are considered light (usukuchi) or dark (koikushi). Dark is more commonly used (think your basic Kikkoman). It has a deeper brown color and greater body, is less salty and used more expansively, say in marinades, to baste meats, and for simmering. Light soy sauce, on the other hand, is more caramel colored, clearer and thinner in consistency, and much saltier and more intense in flavor. So it's used more sparingly. Because it will darken over time once the bottle is opened, buy small amounts to use up more quickly.
I recently received two bottles of traditional soy sauces from the large Mitsuwa Marketplace grocery chain. Among their stores is one near me in the Kearny Mesa neighborhood of San Diego. They also have an online store which sells a greater variety of products, such as these artisan soy sauces.
Indeed, these sauces are alive with flavor. I opened the bottle of Marushima's Kijyouyu Washi and took a whiff. What struck me was how much it reminded me of a good sherry. Because it's fermented, you get a slightly alcoholic sugary rush--even though it contains neither alcohol nor sugar. The flavor, though, is round and deep, matching the deep color of the liquid. It is the essence of umami, that hard to describe fifth taste.
According to the notes I had from Mitsuwa, Marushima has been brewing soy sauce for over 400 years, using organically grown Marudai soy beans. It's handmade and additive free.
Then I opened the Ohara Hisakichi Yuasa. It comes from the city of Yuasa in the Wakayama Prefecture, which is said to be the birthplace of Japanese soy sauce, dating back to the 1600s. This soy sauce also gets a long fermentation time, giving it plenty of umami. It's a little lighter than the Kijyouyu Washi, and I found it much saltier.
This led me to think I had both light and dark shoyus, but it turns out that while the brands both make light and dark varieties, these two are what could be described as medium--or all purpose.
For both, be sure to refrigerate them after opening. You can mix them with a little sesame oil and and seasoned rice vinegar to create a dipping sauce. You can enjoy them blended into a bowl of rice, most typically with a raw egg. This combination creates tamago kake gohan, a popular Japanese breakfast dish. Of course, as my friend Mineko notes, "Never pour any soy sauce over a bowl of rice. It is considered very bad manners. You can add soy sauce to an egg, mix and pour onto the rice, but don't pour it directly on the rice."
Mineko also suggests using the good stuff as an accompaniment for sashimi, adding a few dots on a beautiful cold tofu dish, or brushing it on grilled scallops for a finishing touch.
"I love good soy sauce," she says. "They give such a pleasure to the dish. It's also a lovely gift for a person who enjoys good food."