At high-class restaurants, the minimum required nikiri soy sauce is brushed on to the piece, but at restaurants frequented by the general public, customers dip their sushi in as much sauce (soy sauce that includes chemical seasonings) as they like. In fact, there is a gimmick here. The high-class restaurant provides an opportunity for their customers to eat sushi toppings in the most delicious state possible, but the restaurants for the general population allow customers to eat casually with sauce, a daily necessity. This changes how topping ingredients are selected. If the sushi is going to be dunked into the soy sauce, then the topping must have an appropriate fat content that won’t be overpowered by the soy sauce. Therefore, instead of a coastal tuna, a farm-fattened tuna with oily fat is preferred. It is often said that farm-fattened products are too rich, but it is also said that they have an impact that isn’t overpowered by the sauce they are enjoyed with.
There is a sensor on the tongue that feels the degree of saltiness. This prevents us from eating too much of things that are extremely salty. Chemical seasonings confuse that sensor. The chemical seasoning palliates the degree of saltiness felt by the tongue. Even if you were to, for example, dunk your sushi into the soy sauce and chemical seasoning mixture, it won’t feel salty. If you eat sushi with the sauce, you can take in a high volume of sodium, which is a pleasure trigger for the human body, without feeling the saltiness on your tongue. In other words, it may be more accurate to say that with commoner sushi, you actually drink the sauce, not dip into it.
The most delicious way to eat sushi at restaurants where the sushi chef applies Nikiri (soy sauce perfectly evaporated with sake) for you is just the way it was prepared. However, at restaurants where sauce is not applied for you, the sushi is eaten by dipping it in soy sauce. The soy sauce used for dipping is provided for you at the counter or table. Many restaurants use the same evaporation formula for the dipping soy sauce.
Soy sauce for dipping is put into a small dish for use, but don’t put in too much. It depends on the depth of the small dish, but the diameter of the circle of soy sauce after being poured should be approximately 25mm.
When dipping sushi into the soy sauce, turning it upside down (although it will be somewhat tilted) and dipping the topping seems to be the most common method. If you keep the topping on the bottom when you put the sushi in your mouth, the flavors of the soy sauce and the fish are in complete harmony and the delicious taste spreads through your mouth. There is also an opinion that turning the sushi upside down for dipping is unacceptable practice. There are also some with the opinion that whether to eat with your hands or chopsticks depends on the situation.
Make sure not to get any soy sauce on the Shari (vinegar rice). You don’t want to add unnecessary saltiness to the Shari, which has already been seasoned. It would be a terrible waste to cancel out the exquisite balance of the topping, wasabi and Shari with the saltiness of soy sauce.
There are many different things all over the world that are share the name “sushi”. However, when Japanese people hear this word they think of “nigiri sushi”. Of course outside of Japan, it probably more commonly refers to sushi rolls.
Similarly, the way soy sauce is used also differs greatly between people in Japan and those in other countries. The soy sauced used for nigiri sushi is not used to add salty flavor to the sushi. The reason it’s used is to subdue the fishy odor of the fish and to add the many amino acids contained in soy sauce to nigiri sushi, which brings out the umami synergistic effects. Think of it more like an important background role to the sushi that isn’t meant to stand out. Meanwhile, since sushi rolls and other sushi dishes overseas are generally eaten after being cooled, the flavor is subdued, leading to using large amounts of soy sauce.
There is also a big difference in the concept of sushi sauce. In Japan, there is no such word as “sushi sauce”. Neither chefs nor the general population has heard this term. However, the term is easy to imagine what it would be, so hearing the word “sushi sauce” would probably lead Japanese people to assume it meant nikiri shoyu or nitsume, which are used in nigiri sushi. Also, soy sauce, or “shoyu” as it’s called in Japanese, is not considered to be a type of “sauce” in Japan. But what about in other countries? Sushi sauce has a distinctive, assertive flavor and is added to bring out multiple layers of flavor. There are also many types of sushi sauce such as sriracha sauce, spicy mayo, mango sauce, ponzu sauce, tonkatsu sauce, eel sauce, tamari sauce, teriyaki sauce, dynamite sauce and others. They each play an important role in bringing out the flavors of sushi rolls that otherwise wouldn’t be apparent.
In other words, as the definition of sushi definition changes across borders, the definition of sushi sauce changes too. However, what both sushi sauce overseas and Shoyu in Japan have in common is that they complement the sushi they are used for.
Now we would like to explain a bit about the Shoyu used in nigiri sushi.
Edo style sushi was created during the Edo period in Japan (1804-1830). The expansion of the soy sauce culture of the Edo area (currently Tokyo) had a big influence on the creation of Edo style sushi. In a time when refrigeration and other technology had not yet been developed, soy sauce played an important role not only in taste, but also in preservation. A surprising number of tasks in the Edo style utilize the scientific effects of soy sauce.
First of all, lightly applying just a small amount of Nikiri shoyu (sushi sauce) on the sushi topping, brings out its flavor and creates a glaze. To put it scientifically, this a clever use of the odor eliminating effects of soy sauce, eliminating the raw odor.
Also, long ago zuke (soaking in soy sauce) was also used for fish other than tuna. This was a way to utilize the bacteriostatic effects of soy sauce, which stop the growth of Escherichia coli (E. coli).
Tsume (sushi sauce) represents the thermal effects of soy sauce. By adding soy sauce, mirin and sugar then boiling down, the amino acids in the soy sauce and the sugar react and the goal is to create a delicious glaze and a nice scent that stimulates the appetite.
Adding a small amount of soy sauce when making rolled egg omelets has the effect of enhancing and bringing out the flavor and sweetness of the ingredients.
Soy sauce is generally overshadowed by the sushi topping and vinegar rice, but soy sauce plays an important role in bringing out and enhancing the delicious taste of the sushi.