Konnyaku is the gelatin-like paste made from a tuberous plant (Amorphophallus konjac, かんにゃく、蒟蒻), in English sometimes called "Konjac." Another, less pleasant translation is "Devil's tongue."
Konnyaku is the name of a tuberous plant and the product made from its root. The tuber is rinsed, peeled, sliced, dried and ground into a powder. That powder is next mixed with water until it becomes a gelatin-like paste. Then as a coagulating agent lime is added and the paste is formed into firm but elastic blocks and cakes. These are then boiled, and finally cooled in cold water.
[Konnyaku]
Konnyaku is grown in Gunma, Tochigi and Fukushima. It grows on mountain slopes and after three years bears a large trumpet-shaped flower. This flower, by the way, led to the English name "devil's tongue.". The root is usually dug up after about 3 years, when it is 2.5 kilos heavy.
More than 2,000 years ago konnyaku was introduced from China as a medicine. From the 13th c. on (Kamakura period) it became a popular vegetarian food among priests at Zen temples. In the 17th c. it became generally popular as a meat substitute in soups among commoners.
Konnyaku is devoid of calories and therefore forms an excellent diet food. Rich in dietary fiber, it helps relieve constipation. Itself tasteless, it takes on the taste of the ingredients with which it is served. It has a chewy character and should always be boiled briefly before eating.
Konnyaku can have various colors: made from peeled roots it is pale white (its natural look), from unpeeled roots and usually with the addition of hijiki seaweed it takes on a grayish dark color (its most common look). When chili peppers are added, it has a red color and when green tea powder is added, green. Types of flavored konnyaku are also on the market.
Konnyaku is used in oden (winter hotpot with various ingredients) and simmered dishes. Coated with miso it is like dengaku (originaly dengaku is made from tofu). White or colored varieties are used as vegetarian sashimi ("yama fugu") - these are often eaten with sweet miso sauce.
Thinly sliced into fine, gelatinous noodles it is called shirataki ("white waterfall") and used in sukiyaki. Sliced into slightly thicker strings it is called ito-konnyaku ("string konjac") and used in nabemono (hotpots).