Napa cabbage is one of the most widely produced vegetables in Japan. It is also known as Chinese cabbage, or hakusai in Japanese, and is in season from autumn through late winter. Said to have originated in the Mediterranean region, napa cabbage was introduced to Japan via China in the late nineteenth century. Its cultivation is now concentrated in Japan’s central Honshu, Ibaraki and Nagano prefectures, which together account for around 50 percent of total national production.
Napa cabbage contains vitamins C and K, minerals and dietary fiber, and its high water content, around 90 percent, makes it a good low-calorie diet choice. The most commonly consumed variety has an elongated or almost oval shape with tightly packed, overlapping leaves; these dense cabbage heads can weigh between 2-3 kg (4-7 lbs.). When simmered, napa cabbage turns tender and its natural subtle sweetness is more pronounced, making it a staple ingredient for nabe hot pot winter dishes. It is also enjoyed raw, and its crunchy texture is appreciated in salads or when pickled.