Bluefin Tuna: Ootoro vs Chutoro – What Are the Differences?

The words “Ootoro” and “Chutoro” are enough to make all sushi lovers’ mouths water. These two particularly prized cuts of bluefin tuna occupy the highest echelons of Japanese cuisine. Their rich, fatty taste and melt-in-your-mouth texture create an unrivaled epicurean experience. But aside from being slices of delicious fatty tuna, what truly distinguishes Ootoro from Chutoro? Before we delve into that, let’s first understand the world of Tuna!

Introducing One of Japan’s Favorite Fish – Tuna

For the Japanese, Tuna is not just a fish – it’s an obsession. This island nation consumes Tuna in droves, snapping up a huge chunk of the global supply yearly. With Tuna being so popular, the Japanese have cultivated extremely discerning tastes regarding the taste and texture of their favorite fish. The Tuna family is diverse, with many species swimming in oceans worldwide. There are 4 main sub-species of Tuna, namely:

Northern Bluefin Tuna / Honmaguro / Kuro Maguro

The crème de la crème, Honmaguro commands exorbitant prices for its tender and rich, buttery taste.

Mebachi (also called Bigeye Tuna)

Like most other Tuna, Mebachi can be found in deep waters and can be recognized by the white stripes along its belly. It is often caught in via longline fishing in the waters of the Pacific, Indian and Atlantic Oceans before being processed and deep frozen on board vessels. Almost 100% of the fish comprise of Akami, and it’s a favourite amongst the Japanese!

Yellowfin Tuna

Yellowfin Tuna is also known as Ahi Tuna. This is commonly sourced in the Southeast Asian Region – particularly in Indonesia. It has a firm flesh that takes on a pink blush when raw. While sashimi-grade (when treated correctly), it is often used in canned Tuna products and in conveyor belt sushi restaurants across the world.

Southern Bluefin Tuna

A close relative of yellowfin that inhabits southern oceans. Similar firm textures and pink hue.

The Favourite: What Makes Bluefin Tuna So Special?

When it comes to Tuna, the Japanese treasure one variety above all others – the Bluefin Tuna, also known as Honmaguro or Kuro Maguro. At the market auctions that happen on a daily basis, each fish is graded based on size, catch area, fat content and marbling, colour, shape and overall condition of the fish. And a single Bluefin Tana can sell for astronomical amounts.

Supply factors (such as its migratory nature, long maturation periods, and legislative fishing quotas) and the ever increasing global demands definitely play a part. So, what makes Bluefin Tuna stand out from its Tuna peers? A few key attributes gives this fish its exalted status:

Sheer Size

While Bluefin Tuna can grow up to 4m in length and weigh over 500kg, the average wild-caught Bluefin Tuna weighs in at around 120 to 250kg. Farmed ones tend to be reared for shorter periods and are often slaughtered at around 90 to 120kg. The sheer size of each fish makes it a popular choice for a culinary showcase at sushi restaurants, seafood markets, cultural festivals, events and even professional seminars.

Fat Content

Due to its large size and habitat, Bluefin packs a rich, buttery flavor in every bite with higher fat levels than other Tuna. In the belly loin, Ootoro and Chutoro cuts can be found, while in the back both Chutoro and Akami cuts can be found. This is atypical for Tuna as most back loins only contain the leaner Akami cuts.

This high fat content often translates to a beautiful marbling and textural bliss for Tuna lovers! As the saying goes, fat is flavor, so think of a umami-rich, melt-in-your-mouth texture!

Depth of flavour

Tasting notes often describe Bluefin Tuna as “umami-laden”, “one-of-a-kind” and “full-flavored”. Given that the Bluefin Tuna is also a Obligate Ram Ventilator species, they are in constant motion to facilitate the exchange of Oxygen and Carbon Dioxide. With well-oxygenated tissues, taste and color of the Tuna meat is positively affected. The constant motion – even when in resting state – also contributes to this, and encourages the development of lean but firm muscle tissues.

Being migratory, and thus, being found in depths and temperatures that span different oceanic regions, the species is incredibly adaptable to it’s surroundings. Fish caught at different times of the year are unique and take on the profile of each season. That being said, it is most loved in the late Autumn and early Winter seasons as the fish migrate southwards from the Northern Pacific waters – which bring about a nice balance in terms of flavor and texture!

What are the Differences Between Chutoro and Ootoro?

Similar to Wagyu, a whole Tuna comprise of many different parts – from the belly loin known as Harakami to the back loin known as Sekami or Senaka, and even prime cuts like the Kamatoro. These can all be classified into 3 main categories – Ootoro, Chutoro and Akami.

1. Fat content
2. Colour
3. Texture
4. Flavour

Chutoro is typically contains a fat percentage of 15 to 30%, which translate to a soft pinkish-red meat that is laced with marbling. With a good balance of both meat and fat content, Chutoro tends to be rice but yet still flavorful, making it a perfect cut for Sashimi and Sushi.

On the other hand, Ootoro only comes from the belly loins, and estimated proportion of fat ranges between 30 and 50%. This high fat content translate into a light pink shade, and a soft, creamy and melt-in-your mouth texture. Because fish fat melts are relatively lower temperatures, slices of Ootoro are often served with a nice sheen. Like Chutoro, it is most often served as Sashimi and Sushi, but can also be found torched (aka Aburi) or heated gently with Bincho.

Get Japan’s Favourite Fish Tuna Here in Soshinsen

If you’re a food enthusiast in search of the finest Chutoro or Ootoro in Singapore, look no further—Soshinsen is your ultimate online grocer. We take pride in curating a thoughtful selection of sustainably sourced ingredients from Japan, offering you exotic choices that stand out in quality.

Our premium selections, such as Chutoro and Ootoro, proudly present two of the most esteemed cuts of bluefin tuna—the melt-in-your-mouth fatty belly and the luxuriously marbled back. Though indulgent, these luxurious tuna cuts promise an unforgettable culinary experience. So, the next time your inner chef craves the creation of restaurant-worthy dishes at home, head to Soshinsen for the freshest Tuna in Singapore. Our unparalleled array of impeccably fresh, premium Japanese ingredients serves as the foundation for crafting your culinary masterpieces.