GOTO Haruhiko (Otetsudai Haruko Blog)

Art Director and Food Culture Researcher

GOTO Haruhiko (Otetsudai Haruko Blog)

A reduced salt soy sauce which you can enjoy free from worries about the salt content

I was born in Iwate in Tohoku and since I was a small child I have loved food with a thick taste, and a lot of salt. I neglected my diet over many years, and ended up being hospitalized after having a stroke which was primarily due to high blood pressure. Fortunately, getting early treatment stopped my condition from getting worse. So, I had developed an illness, and as I found out more I discovered it was a life style related disease caused by the ingestion of food.

Since then I have become especially deeply concerned about the effects of salt on the body. For the function of flushing out salt from the body it is best to include potassium in your diet. Potassium has a role to play as it functions to lower blood pressure by stimulating the discharge of sodium chloride, which contains a high salt content. For that reason I regularly try to eat foods which contain a lot of potassium. Potassium intake (*) should be more than 3000mg for men and 2600mg for women.

Fruits and vegetables are high-potassium foods, for example, spinach (100g) has 690mg, and an avocado has 720mg, but a range of foods such as natto (fermented beans) and taro root are also high in potassium. Parsley contains the most potassium with 1000mg, but as we are not rabbits it’s not possible to eat 300g of parsley every day! Though, this doesn’t mean you can cook spinach as a boiled vegetable dish with soy sauce (a Japanese dish) where you have gone crazy with the soy sauce.

This is the real issue at hand. Soy sauce, the indispensable condiment that sits on every dining table in Japan, has the most salt. In soy sauces there is dark soy sauce and light soy sauce, the latter has a weak color but did you know that the equivalent of one tablespoon of table salt is just 2.6g of dark soy sauce compared to 2.9g of light soy sauce? The concentration of table salt in dark soy sauce is 16% against 18-19% for light soy sauce, a difference of about 2%.

Soy sauce, which is increasingly fermented as a manufacturing process, has seen an increase in umami (taste) and flavor, and a darkening in color. Light soy sauce is produced with a higher salt content, and fermentation is stopped halfway through, and it is this that causes the color to be thin. Reduced salt soy sauce is popular, but this doesn’t mean that reduced salt soy sauce is made with just a little salt straight from the start. This is because a fixed amount of salt is needed in order to brew soy sauce without bacteria multiplying.

Reduced salt soy sauce is made from regular soy sauce which once ready is then put through a desalination unit, a process that removes only salt. If the ratio of salt content of the soy sauce is high than the number of times it goes through this process increases. Reduced salt soy sauce is a soy sauce where more than half of the salt content found in dark soy sauce has been removed.

Now, I would like to introduce a soy sauce where salt content has been reduced by 25%, and in place of that salt, potassium has been added. Potassium has the function of flushing out sodium chloride from the body. Earlier I wrote that I like salty food, but because of the high ingestion of salt in my home town in Iwate Prefecture our town is number one in the whole country for its stroke mortality rate. According to The Ministry of Health, Labor and Welfare’s demographic statistics (2010) for every 100,000 people the ratio of strokes leading to death in Iwate Prefecture were 70.1 for men and 37.1 for women, this compares to a national ratio of 49.5 for men and 25.9 for women, meaning it is pretty bad in Iwate.

As a result of Iwate Prefecture having this bad reputation, five of Iwate Prefecture’s soy sauce makers, Asanuma Soy Sauce Shop (Morioka City), Sasachou Brewery (Hanamaki), Yagisawa Syouten (Rikuzentakatashi), Miyata Shoyuten (Shizukuishicho) and Daikoku Soy Sauce (Karumaimachi), got together with Iwate Industrial Research Institute, Iwate University and Morioka University to research a new reduced salt soy sauce and commercialize it. The unrefined soy sauce from each of the five company’s fried bean curd was brought together at Asanuma Soy Sauce Shop, and the final step in the manufacturing process, heating, was completed.

The reason these competitors joined forces was down to all of them having the same feeling that they wanted to create a soy sauce which could remove the stigma of Iwate Prefecture having such a high stroke mortality rate. As a substitute for the 25% reduction of salt, potassium was added, which works to flush out sodium chloride from the body, and they successfully achieved the development of a soy sauce which has the same taste as a normal soy sauce. This soy sauce, in comparison to other products, led to half of the expected salt content accumulation in the body.

This soy sauce was named Reduced Salt Soy Sauce Iwate Kenmin, and the packaging included a picture of Iwate’s mascot called Sobacchi. It went on sale on the 1st of December 2016, and it was such a popular product that it sold out. They are sold in 200ml bottles, one bottle of which is equal to 40 small spoonfuls of soy sauce, and it includes Wakame kelp and Kombu kelp which makes it full of umami (taste). I recommend that anyone who is worried about health tries this!



* According to the Ministry of Health, Labor and Welfare’s publication “Dietary Reference Intakes for Japanese People.”