Sato-imo (lit. "village potato," so named in contrast to another type that was found in the mountains) is the corm of a perennial plant found all-over tropical Asia in many varieties. It is believed to be one of the earliest cultivated plants in the world. It probably originated in the eastern Indian peninsula and then spread both eastwards and westwards. According to the Tabemono no Kigen Jiten, it came to Japan from China in the Nara-period (8th c.) - it is mentioned in the Manyoshu poetry collection -, but there are also people who conjecture that taro was already a staple food of the Japanese in the Jomon-period (10,000 BCE - 300 BCE).
Taro is characterized by a soft, waxy, almost glutinous texture. At the same time, there is no distinctive flavor. Taro has a high liquidity content (84%). relatively little sugar (13%) and is a good source of starch and potassium. In Japan it is considered a propitious food as the corms (oya-imo) have "children" (ko-imo) and even "grandchildren" (mago-imo).
In traditional preparations, taro is simmered for a long time in flavored broth (for example, dashi and soy sauce with optional extra katsuo flakes; this preparation is called nimono). In this form it can be eaten as a side dish called sato-imo-ni, but the sato-imo is also often individually used in kaiseki, the Japanese haute-cuisine. Sato-imo can also be stewed together with meat or fowl, or added to soups. In these cases it is a useful ingredient as it absorbs the flavor of the broth.
[Simmered Taro in Sweetened Soy Sauce]
When using taro, they are first washed to remove soil residue, wiped dry, peeled with a knife (they have a hard skin) and parboiled. The cut surface shows a snowy-white flesh. When this flesh comes in contact with water, it will develop a slightly slimy texture.
Preservation: never put fresh taro in the refrigerator, as they are weak for cold. Just store in a dry and dark place, wrapped in a newspaper. When buying, look for hard ones with the soil still attached; don't buy washed ones as contact with water impairs the taste.