A Winter Favourite: Yama-imo
When the cold weather sets in, many of us get nostalgic about favourite winter meals enjoyed in Japan that are not so easy to find all the ingredients for here in Adelaide—like a steaming pot of oden or bubbling nabe of chicken mizutaki. Curiously, one of the foods at their seasonal peak in winter that I miss most is a vegetable that is eaten raw, yama-imo. Sometimes translated as Mountain Potato and sometimes as Mountain Yam, it is one of the few tubers that can be eaten raw (if your skin gets itchy when peeling yama-imo, that’s a reaction to oxalate crystals, the substance that is the reason why most potatos or yams are not eaten raw). For the record, yama-imo, and its well-known relative, naga-imo, are yams, which are related to lilies and grasses; sweet potatoes (which Americans often call yams), belong to the morning glory family; while our everyday potatos are actually from a different botanical family again, the belladonna family (yes, one of Agatha Christie’s favourite poisons!).
Julienne some yama-imo then dress with soy sauce and bonito flakes, some nori, wasabi or other favourite flavouring, and you have a crunchy, refreshing, nutritious salad. Grate the flesh, and you get tororo, a shiny gelatinous mixture that can be enjoyed over soba noodles or mixed with sashimi on top of a bowl of rice. A few spoonsful added to a batch of okonomiyaki pancake mixture also produces a much better result.
Pale-skinned yama-imo come in a variety of shapes, but the yama-imo now most commonly used is the darker-skinned naga-imo (long yam). As the name suggests, these tubers can grow up to two metres long. They were introduced to Japan from China a very long time ago, but it was only in the 1960s that farmers began to produce them in large quantities—thanks to a new growing system that was invented to get the roots to grow through pipes to make them much easier to harvest.
It’s nice that thinking about something eaten cold still brings back warm memories
Gail Umehara / Wordsmith
During her 16 years in Japan, Gail juggled raising a family with, amongst other things, working as a translation assistant, librarian, and editor. Back in Australia, she continues to work with words as an interpreter, editor and TAFE lecturer.