Real Stories: Usukuchi Shoyu
Japan is a land of fine food artisans who have perfected their craft for generations dating back as far as the Edo period and beyond. Secco Fine Foods is fortunate enough to offer a selection of these amazing products for our customers courtesy of our distribution partnership with Fino Foods. They have curated the Artisan Japanese range by none other than Nancy Singleton Hachisu, a true icon who is at the forefront of bringing these handcrafted and special products to the world outside of Japan. According to Nancy, the fundamental Japanese flavourings can be reduced to an acronym (SA-SHI-SU-SE-SO) taken from the Japanese syllabary: sa = sato (sugar), shi = shio (salt), su = su (vinegar), se = seiyu/shoyu (soy sauce) and so = miso.
Artisan Japanese seasonings are to be added sparingly and thoughtfully, as they are deeply-flavoured and yield consistently satisfying results. Today we take a look at Shoyu, the quintessential Japanese Soy Sauce. Artisan Shoyu is vastly different from most commercially produced soy sauce, as it involves traditional brewing methods which only a handful of producers are continuing to uphold. While Koichuchi Shoyu is the most common soy sauce found in Japan, there are other types of Shoyu which offer even more depths of flavour. One of these is the coveted Usukuchi, the Japanese light-coloured soy sauce, which is quite popular in the Kansai area (the greater Kyoto and Osaka region).
The Origin
Nestled in the northwest of the Harima Plain, Tatsuno city in Hyogo Prefecture (northwest to Osaka) is blessed with a mild climate and is a town with abundant greenery. The river ‘Ibo’ flows through the center of Tatsuno City and on into the Seto Inland Sea, and during summer time is filled with freshwater fishes. Tatsuno City is widely known as the birthplace of Usukuchi soy sauce, where it has been brewed since the 1600s. The underground water of Tatsuno is of the ‘soft’ nature, making it very suitable for making soy sauce.
Koikuchi (dark-coloured) Shoyu (Left) and Usukuchi (light-coloured) Shoyu (Image courtesy: Kohei Shibuya / 279victoriast)
Usukuchi Shoyu vs. Koikuchi Shoyu: The Difference in Colour
‘Usu’ in Japanese means ‘Light’ while ‘Koi’ translates to ‘dark’.
Usukuchi shoyu is quite different from its ‘regular’ counterpart: Koikuchi (dark) shoyu. The former is visibly lighter in colour, but still has a wonderful flavour and smell. From just colour and aroma though, it can seem like that Koikuchi should be saltier than its lighter counterpart. However, Usukuchi is saltier and it has all to do with the fermentation process. Usukuchi takes about one-third the time to ferment compared to Koikuchi, with more salt. The longer the fermentation, the darker the shoyu becomes. And if left to go on for longer, Usukuchi’s extra salt amount can cause the bacteria that faciltates the fermentation to die. The fermentation time is also dependent on the season, with summer taking only 2.5 months because of the heat, compared to 8 months in winter. Getting the right amount of time to ferment to get the desired colour therefore is an art, and there are only a few remaining artisan producers in Tatsuno (compared to 60 beweries before) who are still committed to this art through natural brewing methods.
Usukuchi should not be confused with ‘light/lite’ soy sauce which have a less fat content, as the light in it’s name only refers to the colour.
The high salt content is balanced by the higher ratio of wheat to soy used to make Usukuchi, compared to Koikochi. The wheat contributes a natural sweetness, making Usukuchi great for adding soy sauce flavours to dishes without adding much colour. In fact, a well-made Usukuchi shoyu like Suehiro’s has a distinct rose-coloured hue.
The fermented mash called Moromi (Image courtesy: Kohei Shibuya / 279victoriast)
How it’s Made
Like other forms of Japanese soy sauces, Usukuchi shoyu is made by fermenting soy beans with salt. In addition to soy beans, Usukuchi also calls for lightly toasted wheat, which helps keep the flavour mild, and Mirin. Artisan producers use natural brewing methods and ferment the mash (known as Moromi) of the abovementioned ingredients in ceddar wood tanks. They will continue to ferment the Moromi until the desired colour is achieved, after which it is pressed to make ‘Usukuchi’ shoyu.
Traditional shoyu pressing (Image courtesy: Kohei Shibuya / 279victoriast)
How to Use ‘Usukuchi’
Since its saliter than regular shoyu, Usukuchi shoyu can be a bit challenging for cooks. As a general rule, cooks should add soy sauce to their food, allow the food to rest, and then see how salty it tastes. Salty flavors can develop or mellow after the soy sauce has been mixed with the food for a few minutes, and it is better to be patient than bitterly salty.
Artisan Usukuchi Producer: Suehiro Shoyu
Unfortunately, artisanal Usukuchi Shoyu is, as yet, a challenge to source outside of Japan due to there being such a small number of producers who still make it the traditional way. Most Usukuchi found are not naturally brewed and are commercial interpretation that barely scratch the surface of true Usukuchi-making. While using machines allow for easier control over the colour, it takes a true artisan to naturally brew this product to the desired colour.
Suehiro Shoyu has been brewing ‘Usukuchi’, a light-coloured Japanese soy sauce, using traditional brewing methods since 1879 in their wooden headquaters on the bank of the Ibo river in Tatsuno. They are one of the last remaining brewers in Tatsuno and in the whole of Japan who have been specialising in Usukuchi for more than 140 years.
Aspergillus oryzae, known as ‘Koji Malt’ (Image Courtesy: Kohei Shibuya / 279victoriast)
What sets Suehiro apart is their deep commitment to traditional methods, and the use of local high quality soy and wheat. They also brew in small batches in fiberglass tanks unlike cedar tanks like most brewers, overseen by around 10 experienced staff, called the Kuran, who ensure consistent quality without the use of industrial machines. The wooden building that houses these tanks however, attribute most to the unique taste and flavour of their Usukuchi, as it is home to specific strains of beneficial bacteria, or Koji malt. Even though its easier to control the colour using modern machines, Suehiro insists on their generations of artisanal skills before finally pressing it to make it very delicate and rich Usukuchi.
Renowned Japanese soy sauce sommelier, Keiko Kuroshima, writes in one of her articles that she had not heard of any other breweries that operate with the focus on “naturally-brewed” Usukuchi shoyu like Suehiro. “It's really a battle with 'colour' every day. Because the water of the Ibo River is soft, it is said that the color will be lighter if it is brewed in this land. Filtering and heating, the time of preparation and the brewing period, we have repeatedly researched and improved everything from long ago,” says current President Takuya Suehiro.
‘Kauro Murasaki’ Smoked Shoyu
The Japanese word for ‘Purple’, Murasaki is an old nickname for premium shoyu. The name speaks to the deep, almost purple colour excellent shoyu (and purple is the regal colour associated with the emperor). This inherent preciousness is why shoyu should be used sparingly. With Artisan shoyu, a dash goes a long way to introducing that little hint of umami. Kaoru-Murasaki (smoked soy sauce) is trending in Japan. We investigated dozens and judged Suehiro Shoyu’s to be far superior. Not only is it made with high quality Usukuchi shoyu from whole Japanese soybeans and wheat, but it is one of the few that is naturally smoked directly over cherrywood with time without using additives such as liquid smoke.