Kudzu

Kudzu the Japanese name (more correctly rendered as kuzu) for a leguminous plant, Pueraria montana var lobata, which is native to Japan and the Orient but has been widely cultivated in the south-east of the USA, and has become an aggressive weed. It is mainly grown as animal fodder, but is also the source of a valuable starch.

The starch, which is called gok fun in China and ko fen in Japan, comes from the root. Tsuji (1980) describes its good properties thus:

As a thickener, kuzu starch—extracted from the root of the vine—is excellent: it produces a sparkling, translucent sauce and adds shiny gloss to soups. It has a gentle pleasant aroma, and does its work at fairly low temperatures. Because it is an alkali, it balances acidity, such as found in sweets. Dusted over foods to be deep fried, it yields a light, crisp, almost crystalline snow-white coating.