Yams or “Satsuma Imo” were first introduced to Japan in the rykyu Islands (Okinawa) in 1604 by the Chinese. It was then introduced in Kyushu in 1609, an area that grows 80% of the total Japanese production.
It has been recognized in this country fro a long time for both its nutritional and pharmaceutical qualities.
There are over a hundred species in Japan, but the most popular edible ones (not the ones exclusively used for making shochu) have red skins and light yellow flesh.
My personal favorite is the “Tanekoshima Gold Imo” grown in Taneko Island south of Kyushu. It has the particularity of being red when raw before chaning to a rich golden color when cooked. Among other varieties, the violet yams are getting increasingly popular.
Tanekoshima yam (deep yellow), “common yam” (light yellow) and Murasaki/Violet yam.
The Missus particularly likes to mix the three above as a cold salad with mayonnaise or cream-based dressing.
-Season: September to November
-Main elements: Carbohydrates, Carotene, Vitamin C, Vitamin E, Potassium, Calcium, Magnesium, vegetal fibers.
-Beneficial to digestion.
-Lose very little of its beneficial elements even after a long cooking.
-Choose specimens with nice color and a “fat/roundish” aspect!
-Plunge yam in cold water as soon as you have cut them. They will not lose their color!
-Boil, bake or steam long enough before taking skin off. Discard skin!