Whether you serve it sashimi-style, grilled on a skewer, or as tuna salad, here's what you need to know about the mighty finfish.

By Colleen Rush
March 16, 2012
Photographer: Iain Bagwell

Tuna—by the time most of us see it, it's in a state that belies just how mighty and regal the lightning-fast fish is in its natural habitat: steely, iridescent skin; powerful muscles and razorlike fins that propel it through water; the warm-blooded physiology that allows it to travel across oceans and survive in the coldest depths around the world. Ask any fisherman and he'll tell you that fighting a tuna on the line is one of the most exhilarating angling experiences.

In the United States, the feisty catch is most popular out of a humble can—Americans eat about 1 billion pounds of canned or pouch tuna every year—but in its natural, unprocessed state, tuna is pure luxury on a plate. The meaty, ruby red flesh is packed with heart-healthy omega-3 fatty acids, and it's one of the easiest types of fish to prepare.

Buy it right

Tenney Flynn, chef/owner of GW Fins in New Orleans, has a golden rule for home cooks buying tuna: "The tuna you buy in a grocery store or seafood market should look like the tuna you see in a good sushi bar," he says. Here's more great advice for choosing, inspecting, and storing your fish.

  • Tuna is graded by color, firmness, and fat content. If you plan to eat it raw or very rare, buy Grade 1 (a.ka. "sushi grade") tuna.
  • Sniff before you buy. Tuna, like all good seafood, should have a fresh ocean smell, or no odor at all.
  • Don't buy fish that is slimy or grainy to the touch. This is a sign of old or improperly handled fish.
  • Buy a whole loin of tuna to cut steaks from yourself, or ask for steaks cut from a loin. Whole fish stays fresher longer because there's less surface area contact with the air. The longer tuna stays "intact," the better.
  • Use thawed or fresh tuna immediately, or store it in the coldest part of your refrigerator.
  • To store tuna in the refrigerator, wrap the fish in a paper towel, place it inside a zip-top plastic bag, and place the bag in a bowl filled with ice.

Fresh vs. frozen

Until recently, you could spot previously frozen tuna, because freezing naturally turns the fish brown, says marine biologist Wayne Samiere, president and CEO of Honolulu Fish Company. But now, some processors treat fresh tuna in carbon monoxide before freezing, which turns it a less natural water-melon red. To know what you're getting, ask if the tuna at your fish market is fresh or previously frozen. There's nothing wrong with frozen tuna per se, but if you are serving it raw or rare, fresh is best for taste and texture.