Today, Japan's largest kuzu root powder producer is Mitoku's organic supplier the Hirohachido Company, located at the edge of Kagoshima Bay in southern Kyushu. Hirohachido makes three hundred tons of kuzu root powder annually. This represents about two-thirds of Japan's total production. Fifth-generation president Kazuhiro Taguchi is head of the family-run business, which was founded in 1875. The original shop was in Akizuki, a small town in northern Kyushu. In 1953, the march of civilization pushed the Taguchi family further south to their present location.
Akizuki's climate and water are ideal for processing kuzu root powder. What's more, according to Taguchi, the modern equipment used at their new factory in southern Kyushu subtly changed the quality of the kuzu root powder.
Determined to make the finest kuzu root powder in all of Japan, Taguchi's father left a small group of workers at the Akizuki shop to continue the labor-intense, traditional hand process. The handmade kuzu powder made by Hirohachido Company at Akizuki is appropriately called Akizuki Kuzu.
It is exported by Mitoku and sold in natural foods stores around the world.
The 120-day process of making Akizuki Kuzu begins in December, when the kuzu plant has focused its energy back down underground and its roots are swollen with starch. The backbreaking work of hand digging roots in the mountains and backpacking them to the nearest road continues until the roots begin sending out their first shoots in the spring. In a good year, the roots will have about 13 percent extractable starch. If, however, there has been too much rain, too little sun, or if the previous autumn's typhoon has damaged the plant's leaves, the roots will produce less starch. When the starch level falls below 10 percent, it is not profitable for the Taguchis to process the roots.
The method of separating the starch from the fibrous kuzu root requires that the root be cleaned, cut, mashed, then washed repeatedly in cold water. After this initial stage, the crude gray kuzu paste is transported by truck from the large Hirohachido factory in southern Kyushu to the old shop at Akizuki.
At Akizuki, the crude paste is washed and filtered through silk screens many times to remove plant fibers and bitter tannins. After settling, the kuzu paste is again dissolved in cold water and filtered. The washing, filtering, and settling process continues until a pure white, clay-like starch is formed.
The starch is cut into 6-inch-thick blocks and placed in paper-lined boxes to dry for about sixty days. The drying process is critical. Kuzu cannot be dried in direct sunshine or heated ovens, as this will affect the purity of its color and impair its jelling qualities. Oven drying makes the kuzu too brittle and hard to dissolve in water. Proper drying takes place in a long wooden shed with large windows that are opened to circulate the air. Every few days, the boxes of kuzu are moved around to make sure each block dries evenly.
If the water used during the filtering process is not cold and pure, the kuzu will begin to ferment during drying. Too much humidity will cause bacterial fermentation and totally destroy the drying kuzu. When properly dried, each block of kuzu should contain about 16 percent moisture. Once dried, Akizuki Kuzu is carefully dusted with a soft hairbrush, crumbled, and packaged.
At Akizuki, fifteen workers produce only five or six tons of kuzu-root powder each season. At the large Hirohachido factory, forty-five workers make fifty times that amount.
According to Kazuhiro Taguchi, Akizuki is blessed with an abundance of pure water and a perfect cold, dry winter, ideal for processing kuzu. The result, says Taguchi, is kuzu that is unmatched in purity, dissolves quickly, has superior jelling ability, and gives foods a beautiful satin sheen. When pressed further, Taguchi claims that the molecular structure of handmade kuzu root powder differs from the automated factory product. These subtle differences enhance kuzu root powder's medicinal properties.