What is Funazushi?

Narezushi (mainly a preserved food in which fish undergoes lactic fermentation with salt and rice), in which Sushi finds its roots, can still be found even today throughout Japan. The most famous is Funazushi in Shiga prefecture.

Although it has “sushi” in the name, according to common knowledge of the day, it would be called crucian carp. The sweet and sour smell tickles your nose and it’s almost like pickled crucian carp. When you actually put it in your mouth it fills with an intense sourness and it can only be described as a really sour pickled food. However, the more you eat it, the more you somehow get used to it and in the end it becomes a favorite food that you will even crave. This effect is so mysterious that people even wonder, “Could this have been synchronized at some point with the tastes of our Japanese ancestors?”

Making Funazushi sushi is surprisingly simple. The only ingredients are crucian carp caught in Lake Biwa, rice and salt. First the internal organs are removed from the crucian carp, next it is salted and then it is shade-dried. This crucian carp is packed tightly into freshly steamed rice in a large cask. “Sushizume” refers to this precise situation, and the ingredients are packed in so there is no air inside. If air is let in, the oxygen will cause microbiota to grow. In other words, it will rot. This is the most important thing in making funazushi.

While this cask is left for eight months to two years, special microorganisms will cultivate even without oxygen. These are lactic bacteria and acetic bacteria, which work to change the entire contents into a sour flavor.

After that, the mushy rice is removed from the finished Funazushi, and only the crucian carp is consumed. However, let me reiterate, this sour flavor is intense and complicated. Comparing it to bleu cheese or camembert cheese might make it easier to understand. The taste is so intense that it makes some people sick.

Incidentally, there are records from when Hideyoshi Toyotomi advanced his army to the Korean peninsula (around 1592), that Funazushi from Oumi was presented to soldiers on the front line as a comfort food. This episode illustrates the fact that Funazushi was a dish of pride for the people of the town of Nagahama (where Toyotomi’s castle was located, now part of Shiga prefecture).


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Revision date: July 26, 2021

What is Black tiger shrimp?

Black Tiger is in the category of the largest shrimp that is part of the Kuruma Ebi family and grows to be up to 30 cm. Black Tiger gets its name from the fact that it looks black before it is heated and has stripes like a tiger. The official name in Japan is “Ushi Ebi” but the reason is unknown. The Black Tiger is cultivated heavily in places like China, Vietnam, Indonesia, Thailand and India. It started to be imported from Taiwan in the 1980s to compensate when Japan’s shrimp consumption could no longer be covered by Kuruma Ebi. At the peak, it accounted for 40% of Japan’s shrimp imports. There is a strong impression of shrimp being imported, but small Black Tiger can actually be caught in Japan from Tokyo Bay southward.

Black Tiger has a strong sweetness and firm meat but maintains its plumpness even when cooked with heat. It is known for the red color that appears when heated. The appearance and texture when eating Black Tiger is said to be similar to Kuruma Ebi, which is known to be a shrimp of luxury, so it is a very popular shrimp in Japan. It is used not only as a sushi topping, but in a wide variety of dishes, such as for deep-fried shrimp or Tempura.

For sushi restaurants, shrimp that has been boiled and had the head and shell removed is imported in vacuum-sealed bags. Once defrosted, it can be used as a sushi topping without any further preparations. At conveyor belt sushi restaurants it was even once presented as Kuruma Ebi.

One problem with Black Tiger, which is the mainstream farmed shrimp, is that it has little resistance to illness, and cannot be farmed in the same place continuously. Therefore, Black Tiger farming volume has dropped and currently Vannamei Ebi (Whiteleg shrimp) is becoming a major force in shrimp farming.


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Revision date: July 9, 2021

What is Shiromiru?

The official name of Mirugai is “Mirukui”. The part of the Mirugai that is used as a sushi topping is the siphon that bulges out from the shell. The siphon is separated from the shell and then this is cut through longways, from top to bottom. One Mirugai can only produce four pieces of sushi. It is also nearly extinct from overfishing. While it can still be caught in the Seto Inland Sea and Mikawa Bay, there are fishing limits, which means it is an ultra-high-priced sushi topping.

However, most conveyor belt sushi restaurants offer Mirugai at reasonable prices. The topping on these is quite white. In conclusion, this shellfish is actually Shiromiru (also known as Namigai or Japanese geoduck) and is mainly found in Aichi and Chiba. As the name suggests, the siphon is larger than Mirugai and whiter (“shiro” means “white” in Japanese). There is a certain flavor that is peculiar to shellfish that live in sandy terrain, which some people like and some people hate. However, at less than half the price of Mirugai, it makes a decent substitute.

Unfortunately, the number of Shiromiru is also declining. Now, in order to fulfill demand, Pacific geoduck is being imported from places like Canada and the U.S. and is also called Shiromiru at the Toyosu Market.


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Revision date: July 8, 2021