Kuzumochi (kudzu starch cake) (葛餅)
"Kuzumochi" are Japanese cakes made of kuzuko (kudzu starch).
There is another kind of kuzumochi which is made of fermented wheat flour and mainly eaten in Kanto Region.
Kuzumochi in Okinawa are made of sweet potato starch called imokuzu instead of kuzuko.
Summary
The color of kuzumochi is transparent to translucent and it has a unique texture with smoothness and elasticity. Those with transparent dough wrapped around red bean paste are called "manju" (dumpling) as manju Japanese cakes, which are popular summer desserts because of their cool appearance, and specialties of Hirama-ji Temple in Kawasaki City, Kanagawa Prefecture, Ikegami-honmon-ji Temple in Ota Ward, Tokyo, and Kameidoten-jinja Shrine in Koto Ward, Tokyo.
In late Edo period, people started to call those made of fermented wheat flour also kuzumochi (in different Chinese characters). Though these two kinds of kuzumochi are often confused, those of eastern Japan made of fermenting wheat flour starch and those in western Japan made of hon-kuzu (real kudzu powder) are completely different from each other, including their recipes and historical backgrounds. This kuzumochi are made of starch refined from wheat flour and fermented by lactic acid bacteria, and have a unique flavor. However, the way to serve kuzumochi is similar to that of western-Japan, sprinkled with soy flour or dark molasses.
Recipe
Dissolve kuzuko in water and add sugar to it, then heat it and stir well until it turns transparent. Let it cool in water and cut into pieces of proper size, or shape into round dumplings with wet hands. Serve with soy flour or dark molasses according to your taste. Sugar may be added to the dough, but it tastes much sweeter if sprinkled over the completed kuzumochi. As cooling it in a refrigerator spoils the transparency of the dough and its texture, it is better to cool it with running water or water with ice. Those made of real kuzuko (kudzu starch) keeps transparency and smooth texture even when it is cooled, compared with those made of potato starch, etc.
The hand-made products can be enjoyed only for about two days, but those sold at supermarkets in low prices are added much sugar and have been processed for longer preservation, thus they are enjoyable for somewhat longer than hand-made ones.
Hon-kuzu
The powder produced from the roots of kudzu plant is called hon-kuzu, which has smooth texture and some bitterness originally. It is also said that the medical effect is degraded when this bitterness is weak.
Because the production of hon-kuzu is little and it is expensive, even most of the products sold as 'hon-kuzu' is mixed with starch of wheat, potato, sweet potato and so on.
(Potato has an action to cool down the human body.)
However, in western Japan, especially in Kinki and Kyushu regions, it is relatively more available thanks to many production areas.
Current state of production of hon-kuzu
As to production of hon-kuzu, because of the aging of those who dig the roots of kudzu plant and decrease of natural resource, the ratio of the China-made powder available in Japan is currently increasing.
Regarding the Chinese products, there are many cases to call them Japanese hon-kuzu, which are made of jikkon-kudzu (kudzu plant) imported from China and processed in Japan, or Japanese powder mixed with Chinese one.
The danger of agricultural chemicals left in the roots of jikkon-kudzu (kudzu) produced in China has become a problem.
Currently, the major production area of hon-kuzu in Japan is Kagoshima Prefecture, but you can rely on the three farmers using the products made in southern Kyushu.
* Kuzu-ne roots produced in Taiwan are roots of Taiwan kuzu, those produced in China are root of Shina-no-kuzu (Chinese kuzu), thus, from a botanical standpoint, they are not same species as those produced in Japan.
Current state of indication of raw materials and place of origin of hon-kuzu
Currently, as there is no obligation for hon-kuzu concerning the indication of the raw materials and the place of origin, the indication of hon-kuzu may not guarantee that it is a domestic product, which means that products without description concerning its raw materials and the place of its origin on its product information label may be mingled with those made in foreign countries.