tuna
Tuna
Tuna sold as "ahi" is either yellowfin or bigeye, and both are lean enough that cooking one through turns it grey and dry. The standard treatment is a hard 30-second sear per side over a cold raw center. Toro — the fatty belly, mostly from bluefin — behaves completely differently.
In one line
Almost no fat, so almost no margin — which is why it's usually served raw.
Buy it if
You're slicing it raw for poke or sashimi, or searing it hard and pulling it while the middle is still cold.
"Ahi" is two fish. It is a Hawaiian word applied commercially to both yellowfin and bigeye. Bigeye is fattier and darker; yellowfin is leaner and paler. A label that says only "ahi" is not telling you which one you bought.
Lean is the defining property. Tuna loin carries almost no intramuscular fat, so nothing keeps it moist once the proteins set. Cooked to medium it takes on the color and texture of canned tuna — which is exactly what canned tuna is. Sear it hot and fast, or don't cook it at all.
Color is not freshness. Some tuna is treated with carbon monoxide, sold in the trade as "tasteless smoke," which locks the flesh a bright cherry red long after it would otherwise have browned. It is legal in the United States and banned in the EU and Japan. Buy from someone who will tell you either way.
"Sushi-grade" is not a standard. No agency defines or inspects the phrase. What actually makes fish safe to eat raw is how deeply it was frozen and how unbroken the cold chain was afterwards.
Where it comes from on the animal
| Species | tuna |
|---|---|
| Subprimal | loin, steak, and saku block |
What else it’s called
How to cook Tuna
| Best methods | Sear Raw Grill Smoke |
|---|---|
| Skip | Oven roast Braise |
| Cook to | Seared rare: 30–45 seconds a side over the highest heat you have, center left cold and raw. Anything past that is dry. |
If Tuna is sold out
Common questions
How rare should tuna be?
Raw in the middle. Sear a one-inch steak 30–45 seconds a side over the highest heat you have — you want a cooked band about an eighth of an inch deep and a cold red center. There is no medium-rare stage where tuna is better than raw.
What is a saku block?
A trimmed rectangular piece of loin, cut and frozen so you can slice clean sashimi off it without knowing how to break down a fish. Slice across the grain, at an angle, with the longest knife you own.
What is the difference between ahi, maguro and toro?
Maguro is simply the Japanese word for tuna. Ahi is Hawaiian, used in the US for both yellowfin and bigeye. Toro is not a species but a location — the fatty belly, mostly of bluefin, sold as chutoro and the richer otoro.
Is "sushi-grade" tuna a real designation?
No. Nobody defines or enforces it, so anyone can print it. Ask instead how the fish was frozen: deep freezing is what kills parasites, and unbroken cold handling afterwards is what keeps it worth eating raw.
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