Japan has a long history of making fermented foods, which are an essential part of the daily diet and Japanese cooking. Natto (fermented soybeans), tsukemono (Japanese pickles), shoyu (soy sauce), miso (fermented soybean paste), and gyosho (fish sauce) are only some of the various types of fermented foods you can find in Japan.
Fish sauce is a staple ingredient in many Southeast Asian cuisines: in Thailand it is called nam pla, and nước mắm in Vietnam. The most well-known example in Japan is Akita’s shottsuru, which is made from hatahata, the official prefectural fish. It is one of the three major fish sauces in Japan, along with Ishikawa’s ishiru (made from squid innards) and Kagawa’s ikanago (sandlance) soy sauce. In kanji it is written “塩（魚）汁”, literally “salty (fish) liquid“. It’s popularity extends well beyond Akita, and is an essential part of the local cuisine.
The process of fermentation
Traditionally shottsuru is made from only two ingredients: hatahata and salt. In times when the hatahata catch dwindled, anchovies, sardines, and horse mackerel were used as substitutes. Some breweries prefer not to use hatahata, as they believe other fish produce a better flavour. To make shottsuru, hatahata are salted and placed in a barrel for one to three years and mixed from time to time with a kaibou, a long pole that is used to mix unrefined sake or soy sauce in the process of fermentation. The longer it is fermented, the mellower and more fragrant it becomes. The end-product is a rich amber-coloured liquid. One ton of hatahata only yields 500 litres of shottsuru sauce, so production is done on a small scale.
The history of shottsuru
The history of shottsuru dates back to the early Edo period, when Daimon Suke-zaemon is said to have first made it at his home in Arayamachi, a famous brewing town in Akita City. Shottsuru was used as a staple condiment in many households until the beginning of the Showa era, since soy sauce was a luxury that most people could not afford. Up until fifty years or so ago when hatahata catch was plentiful, shottsuru was also made at home, and people collecting the fish washed up on shore in order to make shottsuru was a common sight.
How to enjoy shottsuru
Shottusru is a versatile sauce and can be used in any number of dishes. One of the most popular ways to use shottsuru is shottsuru nabe. The base of the soup is dashi stock made from kombu (kelp) or katsuo (bonito), plus shottsuru. Hatahata, mushrooms, tofu, winter vegetables such as hakusai, chinese cabbage, are then added to the pot. Usually female hatahata are used for the nabe, as people enjoy eating the fish eggs. In recent years Oga’s shottsuru yakisoba (stir-fried noodles) has also gained popularity. Unlike traditional yakisoba, which is made with a thick, sweet sauce, vegetables, and usually pork or beef, Oga’s yakisoba is made with a salty shottsuru-based sauce, and seafood instead of meat.
Although fish sauce may seem strange or smelly at first, shottsuru has a surprisingly mild smell, and packed with umami flavour. You can find it in supermarkets and gift shops, and most restaurants serving local Akita cuisine will have shottsuru nabe during the winter. Be sure to try out this beloved signature food, along with hatahata, when you are in Akita.