Butter-Basted Sous Vide Halibut Recipe

Halibut is a gigantic flatfish that lives in deep, cold water. They're not terribly fun to fish for (think: reeling up a 200-pound bath mat through hundreds of feet of icy-cold water), but man, are they delicious! Firm yet flaky, with a heartier texture and flavor than other widely available white fish on the market. Its massive size means you can get nice, thick fillets that are as impressive to look at as they are good to eat. There's a reason it's a favorite of restaurant chefs.

Smaller fish carry the risk of severe overcooking when you use high-heat methods like searing. Halibut cooks more like a thick steak—well-browned and crusted on the outside, with a juicy, tender center. And, just like cooking a steak with this method, cooking sous vide can help you nail that medium-rare center every time. Here's how to do it.

What is the Best Temperature and Timing for Sous Vide Halibut?

Halibut straddles that fine line between firm-fleshed fish, like tuna and swordfish, and flaky fish, like cod or hake. When raw, it's fleshy and firm, but as it cooks, it separates into large, meaty flakes that require a bit of finesse if you want to avoid toughening it or drying it out. Like other flaky white fish, halibut meat is composed of layers of firm flesh separated by connective tissue. This connective tissue breaks down as the fish cooks, allowing the firmer muscle layers to separate and flake.

I cooked halibut to temperatures ranging from 105°F to 150°F, in five-degree increments, to gauge how temperature affects its texture. Here are some key numbers.

120°F (49°C) Halibut

The connective tissue in halibut can be unpleasantly tough at lower temperatures, but at 120°F (49°C) or so, it starts to soften up, allowing the meat to separate into distinct layers with a fork. It still has a sort of soft, sashimi-like texture, but it should be tender and moist.

130°F (54°C) Halibut

At 130°F (54°C), halibut flakes quite easily, and the flakes have a much firmer, meatier texture that offers nice chew without being tough or dry. This is my favorite temperature for halibut.

140°F (60°C) Halibut

Halibut cooked at 140°F (60°C) is right on the edge of where I'd want to eat it, exhibiting maximum meaty chew that is just edging into tough territory. This is a good temperature if you like your jaws to work a little bit for a meal.

There's no need to leave halibut in a water bath for longer than it takes to just cook through—a half hour to 45 minutes is plenty for one-inch fillets, and 45 minutes to an hour for fillets up to two inches thick.

How Do You Shop for Halibut?

Halibut are bottom-feeding flatfish that live in deep, frigid waters. As mentioned above, they can grow truly massive in size (up to several hundred pounds), but most you find at the supermarket these days are fish in the 30 to 40 pound range, yielding fillets about an inch to an inch and a half thick. Halibut is pricey, and a rare treat for me, so when I buy it, I like to look for larger fillets cut from near the center of the fish, where the fillets will have a more even shape above and below the central ridge of meat that follows the halibut's spine.

As with most fish, I prefer to have the fish-cutter give me a couple of larger pieces, as opposed to individual portions. Using a sharp chef's knife at home to trim them down into single-portion sizes gives me more control over the finished product.

Should You Cook Halibut Skin-On or Skin-Off?

Though some sources recommend cooking and crisping halibut skin, I typically remove mine, as it can be extremely thick and leathery. (Some further experimentation on crisping sous vide halibut skin is definitely on the horizon!) The nice part about cooking sous vide is that you don't have to have any special knife skills to get that skin off. Once your halibut is cooked sous vide, you can simply peel the skin off with your fingers before searing.

Should You Brine?

Some recipes for sous vide halibut recommend soaking the fish in a saltwater brine before cooking, in order to season it more deeply and to give it a denser, firmer texture. I tried cooking a few pieces of halibut side by side: one plain, one soaked in a liquid salt and sugar brine, one soaked in a plain salt brine, one rubbed (dry-brined) with salt and sugar, and one rubbed with salt alone. For the brined and dry-brined halibut, I tested various brining times, ranging from 15 minutes up to overnight. I cooked each sample of halibut sous vide at 130°F for 45 minutes, then tasted it.

The difference is noticeable, with both the water-brined halibut and the dry-brined halibut coming out with firmer, better-seasoned, and overall more pleasant flesh. I found sugar in the brine to be distracting, though, if you like the added sweetness, there's no harm in it. I prefer dry-brining to water-brining for the sake of convenience: All you have to do is salt your halibut, seal it in a bag, then let it rest before cooking. Half an hour seems to be the magic number—you'll get a strong brining effect, but still keep things moving along in time for dinner.

Should You Add Fat?

When cooking things like steak or chicken, I typically don't add extra fat to the bag—all it does is dilute flavor by removing fat-soluble flavor compounds. With halibut, on the other hand, I do. Not only does halibut flesh absorb flavor better than land-animal meat, but the fat also helps distribute the flavor of any aromatics added to the bag. If you're cooking more than one piece in a single bag, fat will also help keep the individual fillets from sticking together.

This might just be my roots in New England and its buttery broiled cod talking, but for me, nothing goes better with a white-fleshed, flaky fish than butter, so I use some both in my bag and to sear the halibut after cooking sous vide.

Do You Need a Vacuum Sealer?

You don't need a vacuum sealer for sous vide halibut, and, in fact, I wouldn't recommend using one. The powerful suction of a vacuum sealer can put pressure on the soft halibut, leaving it dented and misshapen. Because of the short cooking time and low temperature, a regular old zipper-lock bag will work fine. To seal a zipper-lock bag air-free without a vacuum sealer, use the water displacement method. It's fast, efficient, and tailor-made for situations like this.

To do it, simply place your food in a plastic bag, and seal the bag almost all the way, leaving about an inch open. Slowly lower the bag into a tub of water, holding the opened end above the water level. As the bag is lowered, the water pressure should force air out of it. Just before it fully submerges, seal the bag completely, and you're ready to cook.

How Should You Serve It?

Halibut is delicious seared naked in hot browned butter with aromatics. When searing halibut, I sear with the presentation side down. (That is, the best-looking side—typically the side that you just removed the skin from—should be in contact with the pan.) Some folks like to use clarified butter, or simply oil, which will give you a more delicate golden-brown color. But, just as when I'm searing beef steaks, I enjoy the flavor that a few burnt milk-protein solids can lend to a piece of meaty fish.

I start by searing in butter, then I add some aromatics, like thyme, shallots, or garlic, and baste the fish with the flavored butter, flipping it over just for a few moments to give the second side a touch of color without risking toughening it up. After only a minute or two in the pan, you've got a butter-based, seared, tender piece of halibut that makes a satisfying meal.