Shoyu Soy Sauce

Organic Shoyu Soy Sauce

Mitoku’s shoyu is made with just four simple ingredients: whole soybeans, whole wheat, sea salt, and water. The quality of the soybeans is of defining importance, as these provide the basis for the sauce itself. For this reason, we use protein-rich whole soybeans, whereas most other soy sauces on the market are made with defat-processed soybeans.

Mitoku only works with producers who use traditional techniques and do not use artificial additives such as alcohol as preservatives. These techniques center around three key processes: koji-making, fermentation, and maturation. Of these, the koji-making is of special importance because koji is very rich in enzymes, which break down the raw ingredients and drive the critical fermentation process. This powerful yet delicate microbial culture needs optimal conditions to thrive, and creating the right environment requires experience and careful supervision.

Another key element is the use of wooden vats. These provide the perfect, microorganism-rich environment for the koji-generated enzymes to work their magic over a long period of fermentation and maturation. Every batch of Mitoku’s superlative shoyu can bring out the best in even simple dishes, whatever the ingredients or cuisine.

    Mitoku uses GMO-free whole soybeans

    There is a world of difference between Mitoku organic soy sauces and most other products on the market. The biggest difference is in the raw ingredients. Today, about 80% of the soy sauce produced in Japan uses processed soybeans, which are cheaper, easier to transport, and allow for quicker fermentation than whole soybeans. Mitoku, by contrast, uses only whole soybeans, which provide the full nutritional content of the soybean and take longer to ferment, resulting in a full-flavored sauce loaded with umami-rich amino acids. As Mitoku opposes the proliferation of genetically engineered foods, all of our ingredients are GMO-free.

    Celebrating regional diversity

    Shoyu was already indispensable to Japanese cuisine hundreds of years ago, when means of transport were still scarce in Japan. As a result, each region developed its own unique version of the sauce. At Mitoku, we honor this diversity by providing organic soy sauces from a variety of renowned manufacturing regions.

    Organic Smoked Soy Sauces

    These sensational smoked soy sauces are exciting additions to Mitoku’s shoyu range. Made using a special patented process by smoking our traditionally brewed organic shoyu or gluten-free organic tamari over Japanese cherry wood, these sauces are infused with dramatic and intense flavors, transforming them into exciting, new taste experiences.

    You can discover the best way to use these sauces for yourself by trying them in place of regular soy sauce to taste the difference, then experimenting with any dish you like, such as sushi, grilled dishes, or even smoked foods. Their powerful flavor and aroma mean just a few drops will be enough to enliven any dish.


Mitoku’s shoyu is made with just four simple ingredients: whole soybeans, whole wheat, salt, and water. Through fermentation, these ingredients are transformed into a delicious seasoning with an appetizing aroma and deep, rich color. Each ingredient plays its own special role. The protein content of the whole soybeans supplies umami, while the whole wheat gives the sauce its sweetness and distinctive fragrance. The salt works to protect the shoyu from bacteria during fermentation, and the water must be pure and fresh to produce a good quality sauce.

Traditional shoyu production relies on a series of carefully controlled processes, namely preparation, koji-making, fermentation, maturation, pressing, heating, filtering, and bottling. Below, we outline some of the key processes.


This stage is perhaps the most critical as it will shape the taste and quality of the entire batch. You cannot make good shoyu without good koji.

First, whole soybeans are soaked in water, then steamed. The producers must rely on their years of experience to determine the optimal volume of water and degree of steaming. Once steamed, the soybeans are mixed with roasted wheat, inoculated with the koji spores (Aspergillus oryzae), and stored in a special incubation chamber for a few days to allow the culture to propagate. The temperature and humidity of the room is carefully monitored and controlled to ensure that the resulting koji is fit for its task, which is to kick-start the fermentation process.

Fermentation and maturation

The next stage is to transfer the koji to large wooden tanks and add salted water. The salt halts the propagation of the koji so that its enzymes can instead get to work breaking down the whole soybeans and whole wheat. The fermentation tanks are rich with microorganisms, including lactic acid bacteria and yeast, each playing their own role in the fermentation process. With the ingredients now broken down, the shoyu is left to mature, allowing it to slowly develop the rich flavor, deep color, and complex aroma that is characteristic of Mitoku Shoyu.

Since living microorganisms drive this stage of production, shoyu can differ slightly from batch to batch. Consistency can be achieved, however, through the expertise of the producer. This can be done, for example, by deciding when the mixture should be stirred, a process that supports the work of the microorganisms, and by keeping a watchful eye on the mixture, making adjustments according to changes in weather or temperature. The exact length of the fermentation and maturation process will depend on the producer’s judgement. Once the batch is considered ready, the sauce is pressed, heated, filtered, and finally bottled.

Traditional shoyu can serve to enhance and deepen flavor in any type of cooking.

This versatile condiment can be used with any cuisine at any stage of cooking, be it preparation, during cooking, or at serving, bringing an appetizing aroma, depth of flavor, and color to almost any dish. This is down to shoyu’s unique balance of the five basic tastes: sweet, sour, salty, bitter, and umami. This balance comes from the sauce’s base ingredients and the long process of fermentation and maturation.

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