Nabetaro and the Yamagata Imoni Festival
On cold autumn days, many people in Yamagata warm themselves with a hot bowl of imoni. This soup’s name is a combination of its main ingredient and cooking method; taro potatoes (satoimo) which are simmered (niru). The dish has roots in the Edo period (1603–1867), when boatmen would boil taro potatoes with dried codfish on the banks of the Mogami River, a major waterway that was used to transport trade goods from Yamagata to other parts of the country.
Over the centuries, the dish has evolved, and there are many local variations. It is usually a soy-sauce-based soup with konnyaku (or konjac, a firm gelatin made from mountain yam), long onion (negi), and beef, as well as taro potatoes. Riverside imoni parties known as imonikai have become a regular autumn event, and Yamagata has hosted Japan's largest Imoni Festival since 1989. It is held in September on the banks of the Mamigasaki River, where organizers prepare 30,000 servings of imoni. The recipe from a previous year’s celebration contained the following ingredients:
- 3 tons of taro potato
- 1.2 tons of beef
- 3,500 sheets of konnyaku
- 3,500 stalks of long onion
- 200 kilograms of sugar
- 5 tons of water
- 700 liters of soy sauce
- 63 liters of sake
To carry out such a large-scale effort, they use a huge multiton pot nicknamed “Nabetaro.” After simmering for over three hours, the soup is distributed to smaller pots for serving, using an excavator tractor in place of a ladle.
There have been several “generations” of Nabetaro over the years. Nabetaro II is 1.6 meters tall and 6 meters in diameter, and weighs 3.2 tons. It was used at the Imoni Festival from 1993 to 2018. It now rests along the bank of the Tachiya River near Yamadera.
