The 300-Year-Old Sea Salt Making Tradition of Utazu 

Ministry of Agriculture, Forestry and Fisheries

Salt is a staple in any kitchen. In addition to bringing out the flavors in food, appropriate levels of mineral-enriched salt are also vital to maintaining a balanced diet. Japan is no stranger to salt making either, having employed a variety of salt-making methods for centuries. In the past, the town of Utazu in Kagawa Prefecture flourished as the salt-making capital of Japan, and today, it continues to pass down the traditional irihama-shiki technique honed over 300 years. 

Salt, 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries
Utazu’s salt is produced through a long-held method that utilizes the gorgeous waters of the Seto Inland Sea and Kagawa’s abundant wind and sunlight. What sets it apart is the calcium and potassium contained in the seawater, which create a smooth and full-bodied flavor. Just a pinch in any dish reveals a gentle and rounded deliciousness without any of the sharp or bitter flavor one expects from table salt. There’s simply nothing like freshly-made, natural Utazu salt. 
The Sea of Utazu, 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries
Sea salt making
Most salt produced around the world today is rock salt, but Japan lacks natural rock salt reserves or salt flats necessary to produce it. Instead, Japan’s salt has traditionally used seawater as a base. One might be quick to assume that extracting salt from seawater is an easy proposition, given that the Japanese archipelago is surrounded by the ocean. However, creating sun-dried salt like you might see in Mexico or Australia requires vast swaths of arid land where seawater can be brought in and evaporated by the sun and dry winds. Japan’s narrow landmass, abundant rainfall, and high humidity have made it harder to create salt here when compared to many other countries.
A Scene of the Saltpan in Utazu in Ancient Times, 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries
The history of Utazu salt 
Seawater is only 3% sodium—in other words, a single liter of seawater contains only about 30 grams of salt. This means that boiling off seawater as-is to extract salt is far too inefficient. Japan’s salt makers thus faced a huge challenge in figuring out how to extract salt from seawater using as little energy as possible. The answer was to first create a saltwater concentrate, from which salt crystals could be extracted through boiling. 
Saltpan of Utazu, 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries
During the Edo Period (1603-1868), business was booming in Utazu thanks to the town’s use of a salt making method exclusive to Japan, called irihama-shiki (“salt farm method”). The region’s low rainfall and long daylight hours made it perfect for irihama-shiki salt making, with the practice continuing until 1972. It was in this year that the changing times and technological advancements led the government to prohibit the use of salt fields, signaling an end to Utazu’s reign as Japan’s largest producer of salt. In 1988, however, an irihama-shiki salt field called Fukugen Enden was set up as part of the Utazu-Umihotaru highway rest area and park in an effort to retain this long-held tradition. This ancient salt-making method is used today at Fukugen Enden, and travelers are encouraged to try their hand at salt making themselves.  Let’s take a closer look at how irihama-shiki salt fields work!
Working Tools for Saltpan, 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries
Saltpan, 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries
Saltpan, 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries
Hamabiki (“sand raking”)  
The sand is raked with a tool called a maguwa. This creates horizontal, vertical, and diagonal scoring which helps salt adhere to the sand. 
Saltpan, 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries
Saltpan, 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries
Hamakai (“sand priming”) 
Seawater is poured over the scoring so that salt will adhere to the sand. Workers use a roughly 2 meter long tool called a hamakai-shaku to evenly distribute the seawater, spraying it over the sand in an arc. Seeing a master salt maker skillfully flinging seawater over the sand beds is a sight to behold. They repeat this process each time the sand has dried (roughly two to four times per day). After three or four days, enough salt will have adhered to the sand. Any rainfall before that means workers must start the process over, since rain reduces the sodium concentration of the fields. 
Saltpan, 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries

Irekuwa (“hoeing”)

The salt-sand mixture is collected using a hoe-like tool called an eburi and placed within the nui, a water filtration pen in the center of the field. Lined with bamboo and straw, the nui will be used to create the brine concentrate.

[Anasue (“gap filling”)] The sand-salt mixture within the nui water filtration pen is smoothed flat using a hoe so that the seawater can filter evenly

[Mondarekae (“ladling”)] Workers use a large, ladle-like tool called a mondare jaku to scoop seawater from a hole beside the nui water filtration pen and pour it over the sand-salt mixture.

Pumping Out Water from the Sea, 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries
Pumping Out Water from the Sea, 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries
Agemizu(“dousing”)  
Buckets known as ninai oke are used to pour further seawater into the nui water filtration pen. This dissolves the salt stuck to the sand and raises the salinity of the mixture. Workers may transport up to 900 liters using these over-the-shoulder buckets. This weight is akin to lifting the roof of a house, requiring workers to have plenty of stamina. 
Salt Water, 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries
Raising salinity and transporting brine to the cistern 
The brine solution produced by the salt field is about 10 to 13% sodium. This solution is poured into a condenser which will further raise the salinity to 19%. It is then moved to a cistern next to the kamaya, or “vat shed.” The saline concentrate has a beautiful amber sheen.
Shiogama (Salt Pan), 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries
A Working Scene by Shiogama (Salt Pan), 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries
Kamataki (“vat boiling”)
The seawater concentrate is boiled off in a two-level vat within the kamaya vat shed. A single round of boiling can produce around 100 kilograms of salt. Rather than boiling off the entire solution, the salt is extracted with some liquid remaining in the vat. This liquid solution is called nigari (“the bitters”), and it contains many other minerals originally contained in the seawater. Separating out this nigari is the secret behind Utazu salt’s lack of bitterness and smooth flavor. 
Nigari (Bittern), 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries

Workers can later use the nigari bitters as a coagulant to turn soy milk into tofu.

Salt, 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries
Finishing touches
The boiled-off salt is extracted from the solution and placed in a wooden tray called a shiodoko. Workers then drain away any remaining moisture content from the tray, leaving the finished product. This relatively unprocessed Utazu salt contains high levels of calcium and potassium. Locals say that the best use for Utazu salt is in salted rice balls, appropriated named shio-musubi (“salted rice balls”), but it is also popularly used for barbequed meats, raw fish, salted caramel, and salt candies. 
Salt, 2019, From the collection of: Ministry of Agriculture, Forestry and Fisheries
As concerns over product quality and traceability grow larger by the day, Japan has seen a growing interest, not only in production sites, but in production methods as well. The Fukugen Enden salt field at Utazu-Umihotaru is Japan’s largest salt field with a hands-on workshop. We hope you will come by Utazu-Umihotaru for yourself and try making some Utazu salt the way generations of salt-making masters have made it.
Credits: Story

Cooperation with:
Zaidanhoujin Utazu Shinko Zaidan Utazu umihotaru
Kagawa Prefecture
SAVOR JAPAN


Photos: Misa Nakagaki
Text & Edit: Saori Hayashida
Production: Skyrocket Corporation

Credits: All media
The story featured may in some cases have been created by an independent third party and may not always represent the views of the institutions, listed below, who have supplied the content.
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