In nagashi somen, one of Japan’s most delightful summertime food rites, noodles are sent down a bamboo chute ‘waterslide’ and you must catch your meal with your chopsticks.

It’s a sunny July day on a mountainside restaurant terrace on the island of Kyushu, Japan. A polo-shirted, 40-something Japanese businessman, a long-time friend of mine, is holding a clump of somen – thin, white wheat noodles – aloft in one hand, and beaming at me and his two foodie colleagues, who have joined us for this feast.

Ii desu ka?” Are you ready?

Ichi, ni, san – iku yo!”One, two, three – here they come!

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He releases the noodles into a stream of water that is flowing down a 1.5m-long bamboo chute. We three are seated at the opposite end, and, as the noodles slide swiftly toward us, we plunge our chopsticks into the stream, trying to grab the slippery threads.

Hayaku, hayaku!” – Quickly, quickly! – prim, pearl-necklaced Kimiko-san on my right exhorts herself. “Ahhh, dame da!” – Oh, missed it! – black-suited Eishi-san across from me groans. As more clumps of noodles flow toward us, we gradually lose all reserve, stabbing and laughing as we chase the elusive strands. Eventually we all raise our chopsticks, triumphantly displaying our glistening catch.

We dip the noodles into ceramic bowls of tsuyu sauce, made from bonito soup stock with kombu (edible dried kelp), sugar, mirin rice wine and soy sauce, to which we’ve added flecks of chopped green onions and grated Japanese ginger. Then we pop them into our mouths. The noodles are icy cold and smooth, the sauce adds a touch of onion-ginger pungency and saltiness, and the ensemble slides oh-so-easily down my throat.

Seated at tables around us are families, employees on a company outing and groups of students, all savouring exactly the same thing: nagashi somen, one of Japan’s most delightful summertime food rites.

Nagashi somen is one of Japan’s most delightful summertime food rites

Accounts vary as to where and when nagashi somen began, but the most commonly accepted story is that the ritual was created in the 1950s in the town of Takachiho on Kyushu, the southernmost of Japan’s four principal islands. Takachiho is home to a nature preserve renowned for its green, forested walking trails and a gorge with dramatic volcanic basalt cliffs and plunging waterfalls. It is especially popular in summer when Japanese flock to escape the heat and rent rowboats to explore the shadowed confines along the Gokase River and venture close to the waterfalls.

The story goes that the proprietor of a restaurant called Chiho no Ie, or House of Chiho, located at the southern end of the gorge, had the idea of sending noodles down bamboo chutes to hungry sightseers. Legend says he was inspired by local farmers who used to cool their freshly boiled noodles in summer by sending them down a rock-framed cascade into the local river. Perhaps he was equally inspired by the surrounding bamboo groves and rushing white waters of Takachiho’s famed falls.

Whatever the inspiration, the new nagashi somen, or ‘flowing noodles’, quickly caught on, and other restaurants in the area began to offer the same. Before long, nagashi somen had spread to neighbouring Shikoku and the main island of Honshu, and had become a beloved summer tradition throughout Japan.

I first witnessed nagashi somen by chance two summers ago – serendipitously enough, at Chiho no Ie, although I didn’t realise the restaurant’s significance at the time. I was visiting Takachiho Gorge for the first time, on a tour of Kyushu. My group had stopped to rest at a tourist area where there were souvenir shops and a few restaurants serving shaved ice, soft ice cream, grilled fish and vegetables on skewers, rice balls, and other delicacies.

I heard squeals of delight coming from one establishment and walked over to see what was going on. Children and adults were seated on two parallel wooden benches about 4m long. Between them were two chutes made of split bamboo trunks, also around the same length. At the far end of the chutes, two spirited women in bright aprons and kerchiefs were scooping tongs full of white noodles from woven bamboo containers and dropping them into the clear water that was streaming down the chutes.

As they did so, chaos and laughter erupted as children and adults plunged their chopsticks into the stream, hoping to capture their meal. The somen that survived the gauntlet slid into bamboo baskets positioned at the end of the chutes.

Our tour guide explained that this was nagashi somen and that it was a special summertime treat. Unfortunately, we didn’t have time to try it then, but I vowed to have nagashi somen on my next summer trip to Japan.

Where to try nagashi somen

Perhaps the most famous nagashi somen restaurant in Japan is Hirobun, located in a picturesque mountainside village about 15km outside Kyoto. Here in summer, diners are seated directly above a rushing river, whose white-frothed flow wonderfully complements the streaming noodles. At Hirobun, what you catch is what you eat – the unplucked noodles are not retrieved – and a red-dyed clump of somen signals the end of the feast. 

Fast forward 12 months. I’m back on the island of Kyushu, this time exploring the province of Oita with my friend Ryoji-san, a Kyushu native, and his somen-loving workmates. Months earlier, as we were planning the trip, I asked if we could fit nagashi somen into the itinerary and he gleefully agreed. Which is why we have come to the town of Kokonoe, midway up a densely forested slope in the Kuju mountain range, where a rustic restaurant called Katsura Chaya offers nagashi somen on its terrace.

The setting is part of the pleasure of the experience. We’re sitting in fresh mountain air, surrounded by green trees and blue sky. When I remark on this, Ryoji-san says, “Most nagashi somen restaurants are located in beautiful natural settings, by the banks of a river or by a green forest grove. Nagashi somen is meant to be eaten in nature.”

“The condiments are important too,” Kimiko-san says. “They always showcase whatever is fresh locally. Here we have green onion and ginger, but in other parts of Japan, it might be shiso [a kind of mint], shiitake mushrooms, crab, shrimp or seaweed.”

“How about the somen itself?” I ask.

“Somen was brought to Japan from China in the 8th Century,” Eishi-san responds. “At that time rice flour was used, but in the Kamakura Period, from the 12th to 14th Centuries, wheat flour replaced rice. For centuries, somen was mostly eaten by aristocrats and monks, but in the 18th Century it became widely popular.”

“Somen are the thinnest Japanese noodles,” Kimiko-san adds. “They’re just under 1.3mm uncooked. They’re usually served cold in summer, but they can also be eaten in winter in a hot soup. In this case they are called nyumen.”

“Oh, they’re coming!” she suddenly shouts, as Ryoji-san beamingly sends more noodles our way.

After 15 minutes of mostly futile somen-plucking, I discover that the best technique is not to try to catch the noodles as they pass, but to plant my chopsticks in the stream before they reach me. Then the chopsticks become a kind of mini-dam. Some noodles catch on them and begin to clump up, and this catches other noodles. Before long, I’ve trapped a healthy helping of the elusive strands.

Then I raise my chopsticks, plop the noodles into the dipping sauce and experience a little taste of summertime heaven.

After an afternoon of somen-slurping on the terrace at Katsura Chaya, I’ve come to understand that nagashi somen is about the entire experience: the setting in nature; the cold, flowing water and the white noodles; and the communal effort to catch them. It’s a quintessentially Japanese ritual, marrying reverence for nature, food and community.

As we prepare to leave, I ask the four university students at the next table why they enjoy nagashi somen so much. One bright-eyed woman immediately replies, “On a hot and humid summer day, eating nagashi somen makes us feel like we’re swimming in a cool mountain stream. It’s so refreshing!” Her companions all nod enthusiastically. “And it’s so tasty!” another says and giggles. Then they turn back to the task at hand, chopsticks poised.

At the far end of the chute, a smiling classmate raises a glistening clump of slippery strands. “Ichi, ni, san – iku yo!

The Ritual of Eating is a BBC Travel series that explores interesting culinary rituals and food etiquette around the world.

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