Iwashi Sushi
Pilchard or anchovy

iwashi sushi

What is Iwashi イワシ [鰯]?

In Japan the term iwashi refers to a group of sardines and anchovies. Additionally, many (unrelated) fish include the term iwashi in their name.

In Japanese cuisine, iwashi refers primarily to the Japanese sardine. The term is also occasionally used for the Japanese anchovy or the red-eye round herring. From these three types, the Japanese sardine, whose correct designation is ma iwashi, literally the "real sardine", represents the most important species. The Pacific sardine, in addition to the Japanese sardine, is nowadays being used in Japanese cuisine and can therefore also be considered as iwashi in a broader sense.

All species are of high commercial importance, are extensively fished and industrially processed.

Iwashi for Sushi and Sashimi

Iwashi nigiri sushi with spring onion and ginger.

Iwashi is considered a delicate fish that must be processed carefully and quickly. Since iwashi decomposes rapidly, it develops an unpleasant odor early after being caught and is therefore only available in limited quantities for sushi or sashimi. To maintain freshness iwashi is either soaked in 3 to 5 percent salt water or previously sprinkled with salt and then placed in a mixture of ice water and vinegar. The osmotic effect of the salt solution has a slightly preservative effect, reduces the odor and maintains the shiny skin surface characteristic of iwashi.

With plump in-season iwashi, the fatty layer in between the skin and the flesh is amazingly thick. Despite that, it neither smells fishy nor tastes greasy. Jiro Ono in Sushi Chef: Sukiyabashi Jiro (Satomi, 2016)

Ginger and spring onion are suitable as side dishes, ginger also has a neutralizing effect on the smell. Especially fresh specimens harmonize very well with wasabi alone. In upscale sushi restaurants, ginger and spring onions are sometimes pressed into a paste, refined individually and placed on top of the nigiri coated with soy sauce. If iwashi is prepared as sashimi, soy sauce mixed with ginger is very suitable.

Best Season

The spawning times of ma iwashi depend on the region and population, therefore no exact season can be determined for sardines from the group of ma iwashi. In Japan the months from June to October are traditionally considered to be the tastiest time of year for Japanese sardines. The spawning season of the european sardine (yōroppa ma-iwashi) also varies considerably by region and population, with the main fishing season beginning in late spring and ending in late summer.

Urume iwashi is caught all year round, but it is said that the best season is from winter to early spring, when the fish have become fattier.

Katakuchi iwashi migrates from the East China Sea to the coastal region of Taiwan to spawn in late winter and early spring. Therefore summer is considered the best season for katakuchi iwashi.

Iwashi caught between spring and summer are also considered particularly tasty and are called baiu iwashi (rainy season) or nyuubai iwashi (beginning of the rainy season).

Iwashi in Japan

Several freshly caught sardines (jap. iwashi) lie on a net before being filleted for the preparation of sushi or sashimi.
Like other fatty fish, sardines spoil quickly, so make sure they are very fresh if you want to prepare them for sushi or sashimi.

In Japan, October 4 has been the official sardine day since 1985 (イワシの日). The day was created by the Iwashi Promotion Association (いわし普及協会) with the aim of encouraging the acceptance of sardines as a cheap and tasty fish. In Japanese, October 4th is written as 10月4日, resulting in a pun that reads iwashi (1 → い [i], 0 → わ [wa], 4 → し [shi]) (Kase, 2009).

Ma iwashi マイワシ【真鰯】

The most common iwashi species found on Japanese dining tables is Japanese sardine (ma iwashi), which also serves as a eponym for its associated species. Of all iwashi species, it is most commonly used for the preparation of sushi or sashimi.

The Japanese sardine is a submember of the species Sardinops sagax. Accordingly, all representatives of this species are understood as ma iwashi, literally "real sardine". The population of ma iwashi is divided into five different subspecies, chiri ma iwashi in the waters around Chile, cariforuniama iwashi in California, ma iwashi in Japan, ōsutoraria ma iwashi in Australia and minami afurika ma iwashi around Africa. The European sardine, because of its similarity, especially in taste, is also culinary counted to ma iwashi and is called yōroppa ma iwashi.

Japanese nameCommon name
Ma iwashi
マイワシ
Japanese pilchard
Sardinops sagax melanosticus
Ōsutoraria ma iwashi
オーストラリアマイワシ
Australian pilchard
Sardinops sagax neopilchardus
Minamia furika ma iwashi 
ミナミアフリカマイワシ
Southern African pilchard
Sardinops sagax ocellatus
Kariforunia ma iwashi 
カリフォルニアマイワシ
Californian pilchard
Sardinops sagax caeruleus
Chiri ma iwashi 
チリマイワシ
South American pilchard or Chilean sardine
Sardinops sagax sagax
Yōroppa ma iwashi, Nishi iwashi
ヨーロッパマイワシ, ニシイワシ
European pilchard
Sardina pilchardus

The Pacific sardine usually occurs within large schools in coast-proximity. Young animals feed on zooplankton, adult animals mainly on phytoplankton.

In the years from 2000 to 2018, the Japanese sardine accounted for an average of 21 percent of the global catch of the ma iwashi group. The share of the european sardine was 54 percent. Ma iwashi is mainly used for the production of processed products up to the production of fishmeal, only a small percentage is used as fresh fish.

Diagram showing the time history of the worldwide catch of ma-iwashi from 2000 to 2018

Urume iwashi ウルメイワシ【潤目鰯】

The taste of the red-eye round herring (urume iwashi) is the most distinctive of all sardines belonging to the group of iwashi. Urumeiwashi is therefore very suitable for the preparation of Sushi or Sashimi.

Urume iwashi is caught in much smaller quantities than ma iwashi and katakuchiiwashi. Therefore, urumeiwashi appears less frequently at markets and is therefore rarely found in sushi restaurants. Furthermore, urumeiwashi, like all sardines, is very sensitive and must be processed quickly after the catch. Urumeiwashi is often dried and prepared on a skewer and offered as urumeiwashi no mezashi (ウルメイワシのメザシ).

Urumeiwashi lives in tropical and temperate waters not only in Japan but all over the world. They swim in shoals near the sea surface and feed mainly on plankton.

Katakuchi iwashi カタクチイワシ

The Japanese anchovy (katakuchi iwashi) is the smallest representative of iwashi fishes with an average length of 10 cm. Only the freshest specimens are suitable as sashimi and are highly appreciated for their good taste. A large part of the landed katakuchi iwashi are industrially processed as canned or dried fish. Juveniles or the immature fish fry are prepared into shirasu (しらす) and chirimenjako (ちりめんじゃこ).

Economy

Diagram showing the time history of the worldwide catch omost sushi relevant species of iwashi from 2000 to 2018

Gallery

 

For copyright and author information, see the "Image Credits" section.

Native Range

Source: Kaschner, K., K. Kesner-Reyes, C. Garilao, J. Segschneider, J. Rius-Barile, T. Rees, and R. Froese. 2019. AquaMaps, Scarponi, P., G. Coro, and P. Pagano. A collection of Aquamaps native layers in NetCDF format.

Warnings

As a general rule, do not eat ingredients that are not explicitly labeled for raw consumption.

The naturally have high levels of enzymes causes the meat to let it rot quickly. It is therefore essential to maintain an appropriate cold chain until prompt processing. Histamine is not destroyed by normal cooking temperatures, so even properly cooked fish can still result in poisoning.

Consumption may lead to amnesic shellfish poisoning caused by shellfish that have accumulated domoic acid, a neurotoxin produced by some strains of phytoplankton. Gastrointestinal symptoms can appear 24 hours after ingestion of affected molluscs. Boiling or freezing affected seafood does not reduce toxicity.

References & further reading

  • [Kase, 2009]: Kase Kiyoshi (加瀬 清志). Immediately Useful 366-Day Anniversary Dictionary, 3. Edition (すぐに役立つ366日記念日事典、第3版). Japan Anniversary Association, Saku (日本記念日協会 編、佐久市), Sougensha, Osaka (創元社、大阪市). 2009
  • [Kurashi, 2020]: What is Urume Sardine? What is it and how to eat it! Here's an easy and popular recipe! (ウルメイワシとは?気になる味や食べ方を解説!簡単人気レシピはコレ!). kurashi-no.jp, Periplus Co. Ltd, Tokyo (ペリプラス株式会社、東京都). 2020. Retrieved online on: December 24, 2020: https://kurashi-no.jp/I0020013
  • [Lowry, 2005]: Dave Lowry. Connoisseur's Guide to Sushi: Everything You Need to Know About Sushi Varieties And Accompaniments, Etiquette And Dining Tips And More. The Harvard Common Press, Boston. 2005
  • [Masuo, 1987]: Yoshino Masuo. Sushi. Gakken Co. Ltd., Tokyo. 1987
  • [Satomi, 2016]: Shinzo Satomi. Sukiyabashi Jiro. Vertical Inc., New York. 2016
  • [Sushi Academy, 2017]: Master with video! Preparation and nigiri of sardines (動画でマスター!イワシの仕込みと握り). sushiacademy.co.jp, Sushi Academy Co., Ltd. (すしアカデミー株式会社), Tokyo (東京). 2017. Retrieved online on: December 24, 2020: https://www.sushiacademy.co.jp/archives/25799
  • [Trenor, 2009]: Casson Trenor. Sustainable Sushi: A Guide to Saving the Oceans One Bite at a Time. North Atlantic Books, Berkeley. 2009
  • [Yamamoto, 1990]: Katsuji Yamamoto. Sushi: How to Prepare and Present Over 70 Beautiful Dishes. Smithmark Publishers, New York. 1990

Image credits

Information

Illustration

Drawn illustration for  iwashi

Common names

pilchard or anchovy

Japanese names

  • iwashi (イワシ)

鰛, 鰮, 鰯

Scientific name

Selectio ex Clupeiformes

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