Fact Checked

What is Karashi?

Amanda R. Bell
Amanda R. Bell

Karashi is Japanese mustard made from crushed brassica juncea seeds and horseradish. Unlike European mustard, it is not vinegar-based and is typically sold as a paste or a powder. It is a common condiment and seasoning in many Japanese dishes, such as tonkatsu, and plays a starring role in the Japanese stew oden. It is also a common ingredient used when pickling vegetables, especially eggplant.

Karashi is sold in a tube in paste form and in a jar in powder form. The tube version is ready to use, but the powder form needs to be mixed with lukewarm water until it forms a paste. When used as a dipping sauce, the paste can be mixed with mayonnaise or miso, known as karashi mayonnaise and karashi su miso, respectively. By itself, it is commonly used as a dip for Japanese fried pork chops, known as tonkatsu. In many Japanese steakhouses, this condiment is used to make a mustard sauce that is full of sautéed shitake mushrooms and is a common topper for grilled or pan-seared steak.

Karashi is a primary ingredient in oden, a Japanese stew.
Karashi is a primary ingredient in oden, a Japanese stew.

Oden, a Japanese stew made during the winter, is a mix of several whole ingredients, such as eggs, balls of meat and vegetables, which are simmered in a strong stock for several hours. When served, the chopsticks are dipped in a small amount of karashi before the stew ingredients are eaten, adding an entirely new level of flavor to the dish. Oden is typically served in both Japanese homes and as a quick meal at convenience stores, always with a packet of karashi on the side.

This mustard is also used as an accompaniment to natto, a fermented soybean dish. Natto is a common Japanese breakfast dish, especially in schools. Karashi can also be found in several Japanese salad dressings and is used as a seasoning for mushrooms and leeks.

Outside of being a condiment, karashi can also be used to pickle vegetables. This spicy mustard adds a distinctive level of heat to the vegetables and acts as a preservative when mixed with vinegar. Pickled eggplant, known as karashi-nasu in Japan, is a favorite pantry item in Japanese households.

This spicy mustard can be found in almost every store, restaurant and home in Japan, as well as most Japanese grocery stores in other countries. Karashi provides a definite kick to the taste buds and compliments both mild and strongly flavored Japanese dishes. Whether in powder or paste form, this Japanese condiment is a large part of Japanese cuisine.

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Discussion Comments


@alisha-- Yea, brassica juncea is an Asian variety of mustard.

Unfortunately karashi is not well known in the States. Every Japanese restaurant will carry it but there aren't that many Japanese restaurants in the States and most of them specialize on sushi and karashi is not a sushi condiment.

If you have a Japanese pasta restaurant where you live (unlikely unless you're in a big city), you can find a pasta dish with karashi called karashi mentaiko. Karashi mentaiko is basically fish and caviar spiced with karashi mustard. I absolutely love this dish, it's delicious.

It's hard to know what to do with karashi unless you know Japanese foods. But if you have the opportunity to dine at a Japanese restaurant or steak house, you can ask them to bring you a dish which can be eaten with karashi to get a taste of it. I think it's a perfect sauce, a little tangy and a little spicy.


@alisha- Miso is a paste that is made with either rice, wheat or soybeans. It's used to make soup and one of the most common ingredients in it is karashi. I used to have karashi miso soup almost daily for breakfast when I was in Japan.

I would say that after soy sauce and rice vinegar, karashi is the most common sauce. I think karashi is used more than wasabi, but this may change depending on which region of Japan you are in and which foods are cooked.

You know, Japanese sauces are actually all very similar and most of them are made from several basic ingredients like soy sauce, rice vinegar, dashi (stock), various seed oils and pastes and sugar. You can basically mix and match to come up with an innumerable number and variety of sauces.

Take mirin for example, which is made with rice wine and sugar and pozu made from soy sauce, mirin and seaweed.


One of my friends is currently in Japan, she is working as an English teacher there. I asked her to send a few food items for me because I love learning about and trying different Asian foods. I tend to stare in amazement at the various products when I go to a Asian grocery store but never buy anything because I don't know what to do with it.

One of the things she sent me is a dry 'karashi miso soup'. I understand that it's a soup with karashi, but what is miso?

By the way, what is brassica juncea seeds? Is this a type of mustard?

In the US, most Asian restaurants serve soy sauce and wasabi. I have not come across a restaurant that serves karashi even though the article mentions that it is a really popular sauce in Japan. Which would you say is the most commonly used Japanese sauce in Japanese cuisine?

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    • Karashi is a primary ingredient in oden, a Japanese stew.
      By: uckyo
      Karashi is a primary ingredient in oden, a Japanese stew.