Tips, techniques for how to cook fish, but not overcook it

Of all the theoretically “simple” foods that people may be intimidated to cook, fish is at the top of the list. The most common pitfall is overcooking it. That fish is not necessarily cheap only adds more anxiety to the situation.

“The real challenge in cooking both fish and meat is to get the texture right,” Harold McGee says in “On Food and Cooking.” The goal is to make sure you don’t overheat them to the point that their proteins begin to shrink and push out moisture. That happens at a lower temperature in fish than in meat, McGee says. Most fish reach that shrinking point at 120 degrees and dry out around 140 degrees, though there is some variability depending on the type. McGee says the majority of fish are firm but still moist between 130 and 140 degrees; a few denser varieties, such as tuna and salmon, are particularly juicy at 120 degrees.

If you’re looking to increase your confidence when cooking fish and avoid the dreaded overcooking, here are some of the best, simple, beginner-friendly techniques and tips to help you.

Packet cooking fish

Whether you call it packet cooking or en papillote, the method of wrapping fish in parchment with a splash of liquid, some aromatics and vegetables makes for a no-fuss but elegant meal. At its core, you are steaming.

“The moist heat prevents the fish from drying out, and the steamed aromatics penetrate the fish with flavor,” my colleague Ann Maloney said. “Once the fillets are placed in the folded parchment, they bake undisturbed, so there is no need to worry about breaking up fillets while flipping them in a pan. Finally, I find this method doesn’t fill my house with a fishy scent the way some other methods of cooking fish can.”

This technique works well with a variety of fish, though, as Ann says, ideally with pieces that are no more than one inch thick.

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Slow-roasting fish

If overcooking is one of the enemies of fish, then drop your oven temperature. Slow-roasting “is my favorite way to cook salmon, mostly because the gentle heat makes it almost impossible to overcook the fish,” Samin Nosrat says in “Salt Fat Acid Heat.” Moreover, the technique allows fat to render during cooking and keeps the fish moist. This makes slow-roasting ideal for salmon, which is higher in fat, but Nosrat recommends trying it with steelhead trout and Alaskan halibut.

In her recipe, Nosrat goes even lower, cooking a 2-pound fillet at 225 degrees for 40 to 50 minutes. One helpful point she makes: “Because this method is so gentle on its proteins, the fish will appear translucent even when it’s cooked.”

Poaching fish

Poaching is a gentle cooking method well-suited to delicate foods such as fish, according to Nosrat. “Fish poached in water, wine, olive oil or any combination of the three will emerge with an exceptionally tender texture and clean flavor,” she says.

Poached fish will stay moist while refrigerated for a day or two. It’s nice to eat while cool, as well.

A few tips from McGee: Start moderate-size fillets and steaks in water that’s just below a boil so that bacteria on the surface are killed instantly. He recommends then taking the pot off the heat and adding cool liquid to bring the temperature down to 150 to 160 degrees and letting the fish cook gently. Letting the fish cool in the liquid promotes a moister texture since you won’t encounter the same kind of surface evaporation that happens when a hot piece of fish is exposed to air.

You can also use the approach of leaving the fish over reduced heat, covered, while it cooks.

Confit fish

Think poaching, but with fat. The advantage with poaching in something like oil or butter, McGee says, is that the heat is conducted more slowly and gently because they don’t evaporate and cool the same way as options such as water, wine or broth. Moreover, the temperature is even more stable.

Whole roasted fish

Roasting a whole fish “is beautifully forgiving: Even if you leave it to roast a little longer than it should, maybe to crisp up the skin, the fish stays moist,” says Domenica Marchetti. After experimenting with her first whole-roasted fish, Marchetti found that “the meat was firm and sweet and much tastier than the precut steaks and fillets I’d become used to cooking. This makes sense: Fish bones impart flavor, while the skin keeps the flesh beneath moist as it roasts.”

A whole fish also makes for an impressive presentation, and you can experiment with different ways to season and stuff it.