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Sakai Kelp

The skill and sensitivity of Sakai's kelp craftsmen transforms the bounty of the Hokkaido's seas into processed health foods.

Sakai's kelp processing industry prospers as a key unloading area for Hokkaido kelp


Used at New Year's banquets and in gifts celebrating long life, kelp (synonymous with celebration) has long been part of congratulation in traditional Japanese culture. Kelp production has always been primarily centered in Hokkaido. In the middle of the Edo period, a sea route (called the "Kelp Road") was opened to carry kelp harvested in Hokkaido south through the Sea of Japan to Shimonoseki and through the Inland Sea to Osaka Bay. Tradition holds that the number of kelp processors increased rapidly as large quantities of kelp came to be unloaded at Sakai, which became a distribution center in Osaka. At the peak of the industry's development from the Taisho period to the early Meiji period, the area grew to include more than 150 processors and became famous throughout Japan.

Sakai kelp processing as a force for healthy living


The quality of kelp varies with the beach where it grows, resulting in product with an endless variety of shapes, thicknesses, widths, and flavors. High-quality kelp is generally said to be thick and wide with a good aroma and color, although different varieties are considered best suited to different uses; for example, one variety might be ideal for use in soups but not very good when rolled with fish.
To process dried kelp from Hokkaido into delicacies such as tororo and oboro requires great skill and keen sensitivity in the selection of the kelp used and the determination of how long to pickle it in vinegar, how to slice it with the knife, how to sharpen the knife, and other intricacies. To make the most of kelp whose qualities vary due to differences in the conditions under which the plant is grown requires the unique intuition of highly skilled craftsmen with many years of experience. Slight variations in the force used to cut the kelp with handheld knives gives rise to subtle flavors that are not attainable with automated processing.
Thanks to the explosion of interest in health foods in recent years, kelp is the subject of renewed attention as an ideal health food* with high nutritional content. Sakai's kelp processing industry may be helping to keep us all healthy.

  • Kelp is rich in calcium, vitamins, minerals, and dietary fiber, many of which are often not present in sufficient quantities in the modern Japanese diet. It is also a leading alkaline food that works to neutralize excess consumption of acidic foods such as meat, making it an ideal health food that is rich in the bounty of nature.

Example of kelp processing

(1) Dried kelp from Hokkaido is pickled in a tank of vinegar for 10 to 15 minutes, during which time it is carefully observed until it becomes firm enough for easy processing. The length of this pickling process is adjusted according to the season, temperature of the vinegar, and thickness of the kelp. Processors have continued to use the same stock of vinegar since their establishment, adding to it as necessary over time.

(2) Having been softened in vinegar and allowed to sit overnight, the kelp is passed through a sand removal machine one strip at a time to remove dirt, sand, and other impurities.

(3) Material is cut away from the top and bottom surfaces of the kelp to create oboro. Workers select pieces of the remaining kelp stalks that are free of damage and cut them with a special knife into pieces of a variety of dimensions. The cut kelp pieces are grouped into sets of 100 and cut with cutters of assorted shapes for use in decorative New Year's boxes, matsumae sushi, and bateira sushi.

(3)' Alternatively, material is cut away from the surface of the konbu with a specially sharpened knife to create tororo. The remaining stalks are cut to make oboro, after which any remaining stalks are stored under pressure for two to three days and fermented before being cut again. Kelp cut using any of these three processes becomes either tororo or oboro of varying color, shape, texture, and taste.

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