Kyushu, Japan’s southern island, was the gateway through which ideas and culture spread to Japan from China. As early as the 4th century AD, Buddhism was introduced by monks from the mainland; these same traveling missionaries brought with them their recipes for preparing the simple foods that were so essential for their strictly vegetarian diet. In Kyushu they found that the mild climate, pure water and abundance of excellent rice made it the perfect place to establish the small scale, local production of rice vinegar. To this day it remains a local specialty.

Kyushu’s locally produced specialty vinegar is made from brown rice sake that is fermented in earthenware crocks, which are buried in the ground. The origins of Mitoku Organic Brown Rice Vinegar date all the way back to this unique 1,000-year-old method, which today survives only on Kyushu. This kuro-su (black vinegar) is made from brown rice, with its bran and germ intact, and thereforehas a high concentration of essential amino acids. It is also fermented and aged naturally for over 12 months, which means this product has none of the typical mouth-puckering acidity of most vinegar. Instead, Organic Brown Rice Vinegar has the rich, rounded taste, the smooth, mellow flavor and the gentle, very delicate character that is so essential for the finest traditional cuisine.

The secret of brown rice vinegar is Koji, the unique rice culture that is the vital ingredient in so many Japanese fermented foods. Steamed rice is inoculated with starter spores and then incubated under carefully controlled conditions for up to two days. Turned frequently by hand to ensure its even development, the rice soon is covered by a fine bloom of fragrant white mold: this is Koji, a live culture that transforms and enhances the foods in which it is put to work.

  • Organic Brown Rice Vinegar

    • Organic
    • Kosher
    • Wheat free

    Available in bottles or bulk


Authentic Kyushu brown rice vinegar accounts for less than 1 percent of Japan’s annual 100-million-gallon vinegar production. During the Second World War, a shortage of rice encouraged the development of a much cheaper, quicker process.

The quicker, industrial rice vinegar-making process does not use rice Koji. Instead, it adds sake lees, the dregs left from sake manufacturing, to distilled grain alcohol. This mixture is fermented under controlled temperatures, and, in less than a month, bacteria convert the alcohol to acetic acid (distilled vinegar). Much more than flavor is lost in the sake lees-distilled alcohol process. Since the alcohol is distilled by boiling, most of the amino acids are left behind in the process. According to the Japan Food Research Laboratories, authentic rice vinegar has five times the amount of amino acids as sake lees vinegar.

When shopping for rice vinegar, read labels carefully. The highest-quality products are made from either brown rice or sweet brown rice and water. Although many vinegars found in Oriental food stores are half the price of natural food brands, keep in mind that these lower-priced products are invariably made from distilled alcohol and sake lees. Some brands list wheat, rice, corn, sake lees, and alcohol as their ingredients, while other brands list no ingredients at all. It is impossible to judge the quality of rice vinegar by its color, since some Oriental food brands have added coloring agents.

Ironically, the finest brand Kyushu vinegars, which are offered by Mitoku, may contain a rice sediment, which, if disturbed, makes them look muddy. Rather than being a cause of concern, this sediment is a sign of quality.

Another type of Japanese vinegar, unrelated to brown rice vinegar, is called umeboshi vinegar or ume-su. Colorful and zesty umeboshi vinegar is a byproduct of making umeboshi, Japanese pickled plums.

In his best-selling book Folk Medicine, Dr. D.C. Jarvis, an authority on old Vermont folk remedies, described an unusual experiment. He asked twenty-four people to keep a daily record of the food they ate for two years. They were to check the acid-alkaline reaction of their urine each day using a simple litmus-paper test. Comparing his patients’ medical records with their urine tests, Jarvis saw an apparent pattern. A few days before the onset of an illness, a patient’s urine shifted from acid to alkaline.

The alkaline reaction usually corresponded with eating specific foods. Jarvis was surprised to learn that one of Vermont’s oldest and most popular tonic drinks, two teaspoons of apple cider vinegar and a teaspoon of honey in a cup of water, shifted the urine reaction back to a healthy acidic condition. Old timers, as Jarvis discovered, used vinegar for chronic fatigue, headache, high blood pressure, dizziness, sore throat, obesity, and a host of other ailments that afflicted both humans and farm animals.

Medical researchers now believe it is the amino acids present in vinegar that are partly responsible for its medicinal effects. In particular, these amino acids help counter the effects of lactic acid buildup in the blood, which can cause fatigue, irritability, stiff, sore muscle, and may contribute to disease.

In Japan, scientific interest in the health benefits of traditionally produced vinegar is revitalizing the small Kyushu brown rice vinegar industry. Dr. Yoshio Takino of Shizuoka University, Japan, has confirmed the importance of vinegar’s amino acids. According to Dr. Takino, the twenty amino acids and sixteen organic acids found in authentic rice vinegar help prevent the formation of toxic fat peroxides. He explains that when unsaturated fatty acids from vegetable oils and other foods are heated and exposed to light in cooking or oxidized during metabolism, fat peroxides can form, which contribute to aging and to cholesterol formation on blood vessel walls.

However, for the stouthearted, the following old Japanese tonic is said to be very effective for increasing stamina and maintaining general health. Wash an egg, being careful not to break the shell. Immerse the egg in a cup of brown rice vinegar for two to three days, or until the shell dissolves, leaving the inner soft skin. Discard the skin and mix the egg and vinegar well. Drink a sake cup of this liquid three times a day (after meals). Known as tamago-su (egg-vinegar drink), this is one of Japan’s most potent folk remedies.


At Maruboshi Vinegar Company, the vinegar-making process begins at local sake shops with a thick, primitive-type sake made from only two ingredients: brown rice and spring water. The sake-maker steams brown rice, sprinkles it with spores from an Aspergillus culture, and sets it to incubate in a warm, humid room. The spores germinate and the culture begins to produce digestive enzymes using the brown rice as a nutrient source

After two days, the fermented rice and Aspergillus become Koji (the ubiquitous starter used in most Japanese fermented foods). The sake-maker next combines the Koji with water and cooked brown rice, then pours the mixture into 100-gallon casks.

Gradually, the enzymes in the Koji convert the proteins, carbohydrates and fats of the brown rice into amino acids, simple sugars, and fatty acids. Next, naturally occurring yeast converts the sugars to ethyl alcohol.

After about eight weeks, the thick, heady brown rice sake automatically stops fermenting when its alcohol content reaches about 20 percent, which inhibits yeast growth. It is then delivered to the vinegar shop, where it is mixed with spring water and seed vinegar (good vinegar from a previous batch). Finally, the liquid is poured into casks, where it is left to ferment for a few months and then on to age and mellow for about six months. Once aged, the vinegar is filtered through cotton, flash-pasteurized, and bottled. Then the long Kyushu vinegar process will be completed.

The Kyushu vinegar-maker still has the crocks displayed as their symbol of their roots of vinegar making and the fact that they still proudly observe and follow the traditional long natural brewing methods.

Refreshing and delicious, naturally brewed rice vinegar is a wonderful seasoning. Characterized by a light sweetness, it is full-bodied yet mild, without the sharpness often associated with industrial vinegar. You can enjoy brown rice vinegar in all the ways you enjoy other natural vinegars. A stimulating contrast of flavors, brown rice vinegar brings almost any food to life.

Besides being a mainstay in salad dressings, pickling mixtures, and marinades, rice vinegar also perks up sauces, dips, spreads, and entrées. Japanese cooks add a little rice vinegar to cooked summer rice to prevent it from spoiling. To make beans more digestible, add a little vinegar to the cooking liquid once the beans are tender. Brown rice vinegar also enhances the flavor of grain, vegetable, and fish dishes. It can help balance salt and fats, and reduce cravings for strong sweets.

Related Recipes