Located in a green valley in rural Nara Prefecture, Morino Yoshino has been making kudzu starch (known as kuzu in Japan) for over 450 years. One of the primary uses for kudzu starch is as a thickener for soups and sauces. Kudzu starch is also an important ingredient in wagashi, traditional Japanese confections served during Tea Ceremony. In fact, about 400 years ago when the art of the Tea Ceremony became popular in Japan, demand for kudzu starch increased.
Kudzu starch is made from the kudzu root (see image above), which grows wild in certain parts of Japan. Morino-san sources the root from Nara Prefecture, Wakayama Prefecture and southern Kyushu. In the colder months, harvesters go into the mountains to dig up the roots. They then make a mash out of the roots, and it is this rough, dark mash that Morino-san receives at his factory. Using only spring water and time, Morino-san gets to work purifying the kudzu starch. The process involves slowly (so as not to create heat) mixing the mash with the spring water and then waiting for two days for the starch to settle out. Morino-san then drains off the water, adds back clean water and starts the process up again. In total he repeats this process 10 times over 3 weeks. After a final filtering, Morino-san removes most of the remaining water using a special drying machine and is left with a 2-3” thick layer of kuzu starch (see image below). After a bit more time in a drying room, the process is complete. What began as a dark, murky mash has been transformed into chunks of snow white starch.