The Appeal of Salt

Ms. Aoyama, I understand you are a Salt Coordinator. What led you to pursue this profession?

After graduating from the Faculty of Policy Management, I found the world of food interesting and joined Kagome. I was involved in product development and other areas, but I overextended myself and my health suffered slightly. This prompted me to move to Okinawa, where I encountered Okinawan salt, which was my gateway into the world of salt.

That was about 19 years ago. I then changed jobs to a company specializing in salt business, and my relationship with salt began. In 2012, I established the Japan Salt Coordinator Association, and this year marks exactly its 10th anniversary.

What aspects of salt did you find appealing?

I do many things, but for example, as I collaborated with Mr. Sugimoto last year on an event called "The World of Salt," I find interest in the relationship between cooking and salt, the history of salt from various parts of the world, and also the beauty aspects.

Salt and cooking are truly inseparable.

Even when I give food education classes for children, I deeply feel the importance of salt all over again. I use salt to help children perceive umami. Of course, for us chefs, the way we use salt is extremely important. There is a history of salt in every part of the world, and it is linked to the history of cuisine. Furthermore, fermentation techniques have advanced because of salt, and encounters with locally harvested ingredients have created new dishes and influenced food culture. It is truly indispensable.

My specialty is modern Japanese economic and business history, and colonial economic history. In the study of Japanese colonial economic history, the discussion has mainly focused on pre-war Japan's expansion into Taiwan and the Korean Peninsula and what that caused locally.

While that research is important, I am interested in how Japan, as the metropole, changed due to the colonization of neighboring regions.

In particular, I focus on the supply of colonial primary products in pre-war Japan. As one of these primary products, nearly half of the salt distributed in the mainland during the interwar period was imported or transferred from the colonies. Therefore, colonial salt production was indispensable when considering the salt market in pre-war Japan. That is why I conduct historical research on salt.

So, I am not familiar at all with current salt trends (laughs).

I haven't thought about salt from that perspective much, so it's very interesting. Of course, salt has been made in Japan since ancient times, and there were a vast number of places across Japan making salt in salt pans and kettles.

However, in 1905, to raise funds for the Russo-Japanese War, the "Salt Monopoly System" began, placing salt—which had been freely sold until then—under the control of the Tax Bureau of the Ministry of Finance. From then on, salt pans gradually disappeared in the name of efficiency. But until then, salt was even produced from hot spring water in places like Yamanashi, which is a landlocked prefecture, so it was rare to find a prefecture that didn't produce it.

That's true.

From what I know, salt pans introduced by the Japanese military still remain in Qigu, Taiwan. Does that mean Japan built salt pans overseas during its colonial rule and brought that salt in?

Rather than the military making salt in Taiwan, I believe it's more a case of the military utilizing existing salt pans.

In Taiwan, salt is made in solar salt pans, which differ from the "irihama-style" salt pans used in the mainland. Due to this production method, literature from the early period of Japanese rule describes solar salt as being in grayish clumps. Because its shape differed from the white powdered mainland salt, it was called "gravel salt" and was disliked by mainland consumers.

For example, until the World War I period, the largest industrial consumption of salt by use was for soy sauce brewing, but in the brewing process, salt is dissolved in water to make brine before being added. Therefore, clumped salt was difficult to dissolve. Consequently, many brewers disliked solar salt.

So there are two major ways of making salt: solar salt and the irihama-style.

Broadly speaking, the difference is whether it is boiled in a kettle or not. Salt that is crystallized to the end using only the power of the sun and wind is solar salt. Even if a salt pan is used halfway through, if it is boiled in a kettle at the end, it becomes "sengo" (boiled) salt. It has various names like kettle-boiled salt, but in technical terms, it is classified as sengo salt. With solar salt, as Mr. Maeda mentioned, the bottom is often soil or gravel, so there is a higher possibility of foreign matter getting in.

But I found it interesting to hear that gray salt was avoided back then as "gravel salt," because nowadays, salt from Guérande in France is gray but is extremely popular as a brand salt. Things really change as times change.

That's true. Guérande salt is rich in minerals and brings out the inherent deliciousness of ingredients, so I think it is highly regarded by chefs as well. Now you can even see it in supermarkets.

Recently, there has been a strong natural orientation among consumers. With the raw food trend, there is a preference for foods that are not cooked with heat. In that context, since "sengo" salt is naturally boiled at nearly 100 degrees Celsius, I think the trend favoring unboiled solar salt has become stronger.

In Japan, a law for the 4th Salt Industry Reorganization Project was promulgated in 1971, which mandated that only salt made using ion-exchange membranes could be produced. As a result, only salt that had just the sodium extracted from seawater suddenly began to circulate.

In human history up to that point, the history of using salt that contained minerals other than sodium—what used to be called "sashijio," which was sticky and full of "nigari" (bittern)—is much older.

In that sense, before the introduction of the salt monopoly system in 1905, I think there were various criteria for choosing salt other than the sodium chloride content.

For example, a professional chef like Mr. Sugimoto can use knowledge obtained from exchanging information with other chefs, not just information sent out by ingredient producers, when choosing ingredients. But that is quite difficult for general consumers. In that case, easily understandable information like "appearance" becomes important.

Certainly, it would be difficult for the general public to gather detailed information.

It was the same in the pre-war period. Taiwan salt, which looked different from mainland salt, wouldn't sell. However, that was a problem for the Government-General of Taiwan. The Government-General, like the home government, derived revenue from the salt monopoly system. Therefore, importers dissolved the solar salt brought from Taiwan to the mainland in seawater and boiled it.

Salt that has undergone this process is called refined salt, but in the end, mainland consumers would not eat solar salt unless it was boiled. This was the reality of salt consumption in the mainland, at least until around the World War I period.

So that was the situation.

Under the salt monopoly system, the Monopoly Bureau of the Ministry of Finance abolished many salt production sites across the country during the reorganization of salt production areas in 1910–11. Until then, there were production sites of a certain scale in each region; for example, Miyagi Prefecture in the Tohoku region and Fukuoka Prefecture in the Kyushu region were major salt production areas. Although they were small compared to the main production area in the Seto Inland Sea region, they could supply salt within their regions to a certain extent. However, many of those production sites were abolished, and eventually, the Monopoly Bureau of the Ministry of Finance took on the role of adjusting salt supply and demand for the entire mainland.

And to provide a supply that met the demand for salt in the entire mainland, they ended up in a situation where they had to bring in salt from the colonies.

However, even if they said, "We're short on salt, so please buy solar salt," consumers wouldn't buy it. No matter how much it was under the monopoly system, the government couldn't force people to buy it, so the government had to supply what consumers would buy. Therefore, they had no choice but to process colonial salt into refined salt and supply it as white powdered salt.

With various types of salt available, does the way you use them change depending on the culinary application?

While the primary use of salt is to determine flavor, salt used during the cooking process is also very important.

Fish is a good example. First, you wash the fish and soak it not in plain water, but in salt water with a concentration of about 3%. By doing so, excess moisture and odors are drawn out through osmotic pressure. This maintains freshness. In my case, I use plain water and ice, firming the fish in the ice while soaking it in a high-salinity solution. When I do that, the quality of the fish meat is completely different by the time it reaches the finished state on the plate served to the customer. I feel that kind of appeal of salt while being on the front lines.

Also, since my main focus is French cuisine, I am always taught to "salt" when sautéing vegetables and the like in French cooking. What that means is also osmotic pressure; when sautéing vegetables, the parts where salt is attached to the surface have a higher salt concentration, so the vegetable's own moisture tries to move outward. By moving toward the higher salt concentration—by letting the moisture out—the inherent flavor of the vegetable becomes concentrated. This vegetable cooking method is the first thing you learn in French cuisine.

So osmotic pressure is important.

Perhaps the first French word a chef learns is "Suer." It means "to sweat," and you always add a small amount of salt to make the vegetables sweat when sautéing them. Instead of adding extra moisture to cook them, the way salt is used in French cuisine is to use the moisture the ingredients themselves possess to cook them through.

So you bring out the flavor of the ingredients with salt.

Also, where the salt is harvested greatly affects the taste of the final dish, and it definitely affects the drinks enjoyed with the meal.

For example, a dish seasoned with salt containing a lot of something like calcium would pair well with a wine of the same lineage, whereas if it contains a lot of iron, a wine that reacts to iron would conversely not pair well. Even a single salt affects not just the dish, but also the surrounding environment.

That's quite a profound story. So, Ms. Aoyama, you coordinate the salt when such dishes are being created?

Yes. I ask the chef what kind of dish they are making and what they want to achieve, and then I say, "Well then, let's go with this salt."

I currently have about 2,300 types of salt, and each one has a different personality. The shapes are different, the tastes are of course different, and the balance of minerals inside is different. Since the production methods and origins are different, my role is to choose something that fits the concept or theme of the dish at that time.

2,300 types is amazing. Does that include overseas ones?

There are about 600 salt production sites in Japan alone. However, a single production site doesn't just make one product; they might commercialize only the first salt to form, called "fleur de sel," and then make other products from the salt that forms in the middle or bottom layers, so one site might sell three to four types, or as many as six to seven types of salt.

As a result, domestic salt alone easily exceeds a thousand types. When you include imported ones, it comes to about 2,300 types.

For example, sommeliers use complex expressions for wine, like "nutty." Certainly, since wine has various tastes and aromas mixed together in a complex way, I can understand why the expressions for evaluating it become diverse, but can one perceive anything other than "saltiness" in salt?

When I listen to people researching taste sensors, the data shows that there are various elements besides the so-called "saltiness" of salt. It means there are also bitterness and acidity.

It is often said that since seawater is the same all over the world, the taste shouldn't change. Certainly, from a macro perspective, you could say it's the same, but when you shift your perspective to the micro level, the condition of the seawater when it is drawn as a raw material for salt changes significantly depending on whether it's from offshore with a very fast current or a bay where incoming seawater accumulates in large quantities at the bottom. That affects the taste of the salt.

When Japan built salt pans in Taiwan in the early 20th century, differences in seawater quality were indeed an issue. A Japanese entrepreneur tried to build a salt pan in Kaohsiung Bay in the south, but because a river flowed into it, the salinity dropped below the seawater average. As a result, they couldn't make salt successfully.

When a river flows in, salt production efficiency drops significantly. However, in today's salt market, that is also seen as a point of interest, and attention is also paid to things like the mountains behind the production area. In other words, what the river carries.

Whether it's an iron mine or soil rich in phosphorus. Because minerals from the mountains flow through the river into the sea, the salinity is diluted, but the water is used as a raw material for salt in a state containing various things not found in normal seawater, making it easier to produce salt with distinctive characteristics.

Does using salt with characteristic components change the cooking as well?

If it's at a timing like sprinkling it on during the finishing stage, I think it has quite an impact.

There is an expression "the salt is sweet." I wondered what this was, but among salts, there are some that have a mild taste. I think some people perceive that as "sweet."

That's right. I think the perception of "mild = sweet" is common. Sodium is the mineral that presents "saltiness," but if it contains only sodium, it becomes a sharp, piercing saltiness. Since that is treated as normal for modern people, when compared to that, if the saltiness becomes mellow due to the presence of minerals other than sodium, it leads to the expression "sweet."

Also, salt containing many minerals other than sodium has the effect of working in combination with organic matter, in addition to providing saltiness. Especially when used for preparation, some salts decompose amino acids quickly while others do so slowly during the resting period, so even with the same meat or fish, if you prepare them with different types of salt, the finish will be completely different.

That's true. Though using them differently is difficult.

Because the recognition of salt = sodium lasted for a long time, research into how minerals other than sodium are involved in fermentation, aging, and the decomposition of umami hasn't progressed much yet. I think it will be interesting as that is clarified. The color development of meat, for example, changes significantly.

You mean it changes depending on the type of salt?

This is only based on empirical rules, but if you prepare food with salt high in magnesium—salt containing a lot of so-called "nigari"—it can turn a bit gray. When that happens, the taste is delicious, but because of the appearance, the total deliciousness decreases. It's very delicious if you eat it with your eyes closed, but I don't think that's what cooking is about, so it's a world of searching for the optimal solution there.

Probably people don't go that far in home cooking, so I think that becomes the world of dishes that chefs provide to customers in restaurants.

That's right. That might be the realm where we operate to maximize the appeal of ingredients.

Mr. Sugimoto, how many types of salt do you usually use?

In normal times, about three types. Ones that aren't that expensive and can be used in large quantities. Also, salt called rock salt and the clearest first crystals called fleur de sel. I keep those in stock.

Another thing I'm careful about is the timing of use. I use different timings for when I want to deliver the sensation of the salt and the taste of the ingredients that the salt brings out to the customer at the end, versus the timing in the cooking process.

Personally, I also have several types of salt. I love salts where you can enjoy the texture of the salt alone, and among them, I often use Maldon salt from England. If it's a salt with a bit of smoke in addition to the texture, it adds more depth to the dish and makes it very delicious.

When pairing salt with food, it's not just the taste, but the mouthfeel and texture that become very important. When we think of salt, we tend to imagine white grains, but there are also large, spherical, pearl-like salts and various other shapes, so the texture changes considerably depending on the salt.

Quite a few people use different salts for seasoning beforehand versus as a topping. It's interesting to pursue that aspect as well.

Also, I find salt very interesting because it is such a unique market. In the modern salt market, the price of the product basically does not correlate with quality at all. Cheap salt isn't necessarily bad, and expensive salt isn't necessarily good.

Until the end of the salt monopoly system, the market for so-called table salt was sold at a fixed low price for a long time. It was sold for about 100 yen per kilogram, and since table salt accounted for most of the market, the pie for other types of salt was small.

However, today, about 20 years after the end of the monopoly system, the market for what is commonly called natural salt or sea salt, which costs about 500 yen per 100 grams, is expanding. Even if the consumption of table salt decreases, the overall market doesn't shrink much because that specific market is growing.

This is a pipe dream, but if a world comes where everyone chooses salt as a luxury food item and it becomes normal to buy salt for 500 yen per 100 grams, the market size would suddenly become 50 times larger. No other food has a market with this kind of hidden potential. Depending on how public relations are handled in the future, I think there is a possibility that the market size will expand dramatically.

When expressing that there is no relationship between quality and price, I wonder what the elements that constitute "quality" are. Under the monopoly system, it was very simple; basically, a high sodium chloride content was the measure of quality.

However, that might be a way of thinking unique to the monopoly era. Before the monopoly system was introduced, measuring the sodium chloride content of salt was much more difficult than it is today. Therefore, prices changed based on information about the production area and whether the packaging was a straw bag (tawara) or a woven straw bag (kamasu).

I suspect that the current salt market is no longer in a situation where "sodium chloride content is the sole measure of quality" as it was during the monopoly era. If so, rather than saying there is no relationship between quality and price, it might be that the criteria for judging quality have become extremely diversified.

That may be true. To explain why Ako salt became a brand: during the monopoly era, permission was granted in 1973 for reprocessed salt—meaning, "it's okay to sell salt imported from overseas if you process it again in Japan." At that time, people who were involved in the movement to restore natural salt, which later became the parent body of Ako no Amashio, decided that even if it was overseas salt, they would start making it if they could process it into something close to traditional Japanese salt. That was the beginning of Ako no Amashio and Hakata no Shio.

Then, people who wanted to eat traditional-style salt started choosing these two. Later, Ako no Amashio took a stronger approach toward processed food manufacturers, while Hakata no Shio focused on the culinary industry, so they gradually carved out their own niches. If you ask people in the culinary industry, Hakata no Shio is more common than Ako no Amashio, isn't it?

Yes. It might be common in the professional world.

Regarding what makes quality superior, I think the interesting thing about salt is that there isn't one absolute brand. For example, a salt that pairs well with grain-fed Wagyu beef will often have a taste that is too strong and overpowers the flavor of red sea bream sashimi if used there.

So each has its own characteristics depending on the application.

Yes. For example, recently there has been a trend toward preferring salt with a high "bittern" (nigari) content, but because it's sticky, if you use it as a sprinkling salt for yakitori, it falls off in clumps, so you can't grab it with your fingers and sprinkle it skillfully.

You end up over-sprinkling it.

As a result, it becomes extremely salty. I think the quality of salt can change depending on the application.

Nowadays, across Japan and the world, various salts are available in sizes perfect for souvenirs. I find that very appealing. Even people who have never visited a place can use the salt from there; it makes a great gift.

Recently, as part of pursuing food diversity, the Imperial Hotel has been exploring plant-based cuisine for vegans. When considering where Japan, an island nation, gets its umami, it is ultimately kombu (kelp).

Since bonito is animal-based and cannot be used, we turn to kombu. Kombu is, of course, something from the sea, and when cooking with it, I find it very appealing to use salt from the same seawater where the kombu grew for the final seasoning of the dashi. Even if you haven't been there, it's an attractive way to use it that connects you to tasting that environment.

I understand that very well. It's like saying the origin or the lineage is the same. Rice, in particular, tends to be strongly influenced by its place of origin. That's because it grows with water. And it naturally pairs well with salt made from the seawater of the ocean where that water system flows into.

It's like having the same DNA. And that way of thinking probably aligns with the preferences of those who eat natural, basic, or plant-based/vegan diets, so I feel it will increase in the future.

Yes. I feel that the appeal of such diverse salts in food has more and more possibilities.

Are there many chefs around the world who say that Japanese salt is wonderful?

I spent a long time in France and also worked in London, but I haven't met a chef who uses Japanese salt because it's good.

That might be because they have very high-quality local salts in various regions, and perhaps it's a national trait, but they promote their own products, bring good things to the world, and take pride in using what they produce themselves.

I think so. France, in particular, has an incredible love for its own country. Besides the famous Guérande, there are other good salt-producing regions, and even within those, you can get about 20 types of good salt, so I think they feel there's no need to go out of their way to use products from other countries.

Conversely, Japan is very unusual. Japan is the only country where, even at the general household level, people import salts from other countries so extensively and use them selectively, saying it's not this one or that one.

As a recent trend, are there more individual consumers seeking foreign-produced salt?

I sense a feeling that using pink rock salt somehow makes one feel "fashionable." It has become an everyday item that boosts one's desire for self-approval, like "I'm particular about salt, I'm thinking about my health, and that's a bit cool." I'd be happy if today's talk helps you, Mr. Maeda, awaken to the charm of salt even a little (laughs).

When I say, "I study the history of salt," I'm often asked, "Which salt is good?" and I'm at a loss for an answer (laughs).

You definitely get asked that.

Once, when I visited a sushi restaurant, the owner spoke very passionately, saying, "I use this kind of salt." But I had no idea what he was talking about (laughs).

As you mentioned, I think there's a sense that using pink salt is somehow cool. However, there was a shop that labeled that pink salt as "sun-dried salt from the Himalayas." I thought, "What on earth is sun-dried salt from the Himalayas?" and felt there was some confusion in the information. They probably can't distinguish between rock salt and sun-dried salt.

I hear stories like that quite often. It's only been about 20 years since liberalization, and on top of that, there are many small-scale operators, so there isn't much information dissemination, and it feels like information about salt hardly reaches consumers.

For example, when TV or magazines occasionally do a feature, they might broadcast things that make me think, "Wow, that's wrong," and on social media, everyone says whatever they like, so I think a considerable amount of incorrect information is being circulated.

From the perspective of someone doing history, I feel that salt is prone to becoming like that. Originally, salt was often used as a means of preservation in the era before refrigeration. For example, by salting all fish to prevent spoilage, fishermen were, in a sense, professionals in the use of salt.

However, during the Meiji period, fishermen in Hokkaido intentionally procured poor-quality salt. This was of course due to its low cost, but there were other reasons as well. Some fishermen in Hokkaido believed that it was the bittern components, not the sodium chloride, that were effective in preventing spoilage. In other words, the false knowledge that salt with a lower salt concentration would last longer had spread.

Therefore, when exporting furs such as fur seals to Europe, they sometimes used salt with a low salt concentration for preservation. As a result, the furs would rot when passing through the equator during transport.

It was only then that they finally realized their mistake and noticed they should use salt with a high salt concentration. Precisely because salt is so familiar, it may be that urban legend-like rumors spread easily.

Mr. Sugimoto, how do you want to express the charm of salt in your cooking from now on?

Expressing new cuisine through salt might be quite difficult, but I think professionals have faced salt in various ways for cooking, for the cooking process, to make food delicious, and for preservation.

I think if the ways professionals have interacted with salt, passed down through generations, were to become more public and widespread, it would be an opportunity for everyone to rediscover the charm of salt. I hope to spread the word, even a little, that using salt in this way is of course good for the body and good for the ingredients.

I want to face various ingredients and also work on social issues such as food loss. I want to continue pursuing the idea of "becoming healthy by eating" and the way food should be. Even in the luxury spaces of the services we provide, I am currently exploring whether such things can be considered and provided as luxury value. In that regard, I believe salt will become an indispensable item.

Salt is a product whose self-sufficiency rate in modern Japan dropped quite early. In the pre-war period, supply depended on colonies, and after the loss of colonies due to the defeat in the war, it has depended on other countries. Currently, we depend on Mexico and Australia.

One of the factors for this low self-sufficiency rate was policies by the Monopoly Bureau, such as the consolidation of salt-producing areas. And as Mr. Aoyama mentioned earlier, a unique Japanese market has been established today where various overseas salts are widely distributed, from first-class restaurants to general households. I thought that one of the factors for the establishment of such a characteristic market might be related to the Japanese way of consumption, where salt has been ordered from overseas and used for over a century.

I think a wide variety of topics came up today, and I believe this "variation" in the conversation is precisely the charm of salt. Salt has been deeply involved not only in health but also in the food culture, history, and economic development of each region. It is also used in beauty. I think the fun of salt lies in having so many different perspectives, and I want more people to know about this variety of enjoyment.