The kuzu plant is one of the largest vegetable roots in the world, the average weight of each is around 90kg.
Its leaves and root have long been used as a food and its fibrous stems, as threads for fabrics and baskets.
Kuzu is made from the starch extracted from the root, and used as a natural thickener that do not contain any gluten. Kuzu is produced by the Hirohachido Company based in Kyushu, the Southern island of Japan. They still make it using age old and entirely natural techniques. The 120-day long process begins with the manual, backbreaking harvest of these gargantuan roots, from December to early spring when starch levels are at their greatest. Once recovered, the roots are cleaned, chopped, mashed and washed several times in cold water. At this stage the kuzu takes the form of a grey paste, which is repeatedly washed and filtered through silk screens to remove fibres and tannins. Next, the paste is redissolved and filtered several times, until a pure white starch is obtained. Then comes the drying process, where the starch is cut into 15cm thick blocks and left to dry in boxes for up to sixty days. In order that the finished kuzu is pure white and colour and has optimum gelling properties it must be dried in low humidity, out of direct sunshine and at ambient temperature.
Once dried, the kuzu blocks are crumbled and packed. This Herculean effort is worth it as the result is one of the most effective natural thickening agents in the world, which can be used in a wide variety of cooking. Kuzu also offer a number of health benefits, such as relieving digestive discomfort and even helping to reduce blood pressure.
Kuzu is often cited as an effective hangover cure, due to the presence of flavanoids that can dilate constricted blood vessels.
Kuzu should not be confused with arrowroot, potato starch, and corn starch. Corn starch, in particular, is not recommended because it is highly processed and treated with chemical bleaches and toxic extracting agents. Potato starch is also mass-produced, and chemicals are used to accelerate the extraction process. While arrowroot is made by a simple, natural process, kuzu is far superior in jelling strength, taste, texture, and healing qualities.
Kuzu, or known in America as kudzu root, has been prized for its medicinal properties in China and Japan for thousands of years. In America we know it as “the weed that ate Dixie” covering most of our southern states and proving impossible to eradicate. It was first brought to the U.S. in 1876 as part of the Centennial Exposition in Philadelphia by the Japanese government as part of their garden display. Later kuzu was used in the U.S. for erosion control and that’s when it spread its 200 pound roots and flourished. In 1972 the USDA officially declared kuzu to be a weed and set about researching methods for its destruction. Meanwhile, those in the know pay top dollar for kuzu root to be imported to the U.S. for cooking and medicinal purposes.
A member of the legume family, the kuzu root produces a starch-like powder that can be used as a thickening agent in place of cornstarch or arrowroot powder. The rubber-like kuzu vines are used to make strong baskets and the leaves can be eaten and used in recipes. Clinical studies, done in China, have shown that kuzu root preparations can reduce high blood pressure, relieve chronic migraines and ease aches in the shoulders and neck. The flavonoids in kuzu have been shown to lower cholesterol levels, reduce the risk of blood clots, and protect against heart disease. As reported by Harvard medical researcher Wing-Ming Keung, kuzu can curb the desire for alcohol and help heal the organs damaged by alcoholism.
In his book, Macrobiotic Home Remedies, Michio Kushi recommends using kuzu in the following ways:
- To relieve tiredness and restore vitality.
- To treat digestive and intestinal issues such as indigestion and colitis.
- For colds, which are often related to intestinal weakness.
- As a drink to relieve over acidity, bacterial infection and excess water
- in the case of diarrhea.
- To bring quick relief from abdominal pain and intestinal irritation.