Tempura Scraps Floating in Udon: How Did We End Up Eating Them? [Delicious Stories]

A Byproduct Left Over from Making Japanese-Style Tempura

Difficult to Dispose of Due to Rancidity and Fire Risk

Its Distinctive Flavor Helped Make It an Official Food Ingredient

Editor's NoteThe first confectionery is said to have been discovered in the ancient Mesopotamian civilization. In a sense, sweets have accompanied humanity through every moment of its history. From biscuits and chocolate to ice cream, we bring you delicious stories about the treats we love.

Japanese-style udon has a distinctive topping: round, bead-like tempura scraps. In Japan, people sprinkle these scraps not only on udon but on all kinds of noodles, and even on rice balls and dishes made with hot tofu.

Tenkasu, tempura scraps added to udon. Website of the online Japanese food store Japanese Taste.

The official name for tempura scraps is tenkasu, a combination of the Japanese words for tempura and scraps. In other words, even in Japan, tenkasu is treated as leftovers or a byproduct of making tempura. How did these scraps come to be embraced as a proper food ingredient in Japan?

Batter Drizzled into Oil... What Are Tempura Crumbs, or Tenkasu?

Tenkasu forms when tempura batter is dropped into hot oil. YouTube screenshot.

Tenkasu is a byproduct of the distinctive cooking method used to make Japanese-style tempura. Unlike the battered and fried foods sold at Korean snack shops, Japanese tempura is known for its light texture, created by filling the batter with plenty of air. To achieve this texture, tempura chefs first heat the oil and lightly sprinkle in some batter.

The batter dropped into the sizzling oil scatters into round pieces and hardens, forming tenkasu. Chefs wait until the tenkasu floats to the surface before they start frying the actual tempura. As the tenkasu clings to the tempura, it gives it the soft texture characteristic of Japanese-style tempura. In this sense, tenkasu forms both during and after the making of Japanese-style tempura. That is why, in Japanese restaurants that serve tempura, piles of tenkasu can be found throughout the kitchen.

From a Tempura Shop Nuisance to an Official Food Ingredient

Factory-made tenkasu. Nakagawa website.

Tempura is believed to have been eaten in Japan as far back as the Edo period (17th to 19th centuries), and tenkasu is thought to have been made then as well. Stories are also told of cash-strapped students who, during Japan's post-World War II period of rapid economic growth, sprinkled tenkasu from tempura shops on their rice while studying.

Generous tempura shop owners are said to have shared tenkasu with customers as well as their poorer neighbors. There was a practical reason for this: because tenkasu is made from batter, it quickly turns rancid when exposed to the air. It is also highly flammable because it absorbs a lot of oil. For tempura shops, piles of tenkasu in the kitchen could be a nuisance.

So when did tenkasu move beyond being scraps and become an official food ingredient? According to Nakagawa, a Japanese company specializing in tenkasu, as recently as the early 1990s, tenkasu was a specialty ingredient handled only by tempura shops. The company said on its website, "About 30 years ago, it was still an era when you couldn't buy tenkasu at a supermarket," adding, "Tenkasu was something your mother might bring home occasionally after visiting the neighborhood tempura shop."

However, as demand for tenkasu grew, some companies began setting up factories specializing in its production. This was because the popularity of flour-based dishes such as takoyaki, udon, and okonomiyaki was rising rapidly in Japan. Tenkasu, once an occasional treat added to these dishes, had at some point become a topping that had to be included.

Sprinkled on Rice, Soup, and Tofu, Too

A rice ball made with tenkasu. Nakagawa website.

Today, tenkasu is added to all kinds of food in Japan. It can be used as a topping for miso soup, a Japanese-style soybean paste soup, or sprinkled over a dish made by mixing natto, a fermented soybean dish, with wasabi and mayonnaise. It also features as the main ingredient in home-style dishes such as tenkasu rice balls and tenkasu rice bowls, and is sprinkled over hot tofu as a snack to accompany drinks.

Nakagawa explained that tenkasu is so popular "because the oil in the batter spreads into other foods and adds umami," adding that "tenkasu goes especially well with rice and soy sauce."

This content was produced with the assistance of AI translation services.