Fish is one of the best foods you can cook sous vide. The flesh of fish is delicate and easy to overcook with traditional techniques, but cooking sous vide ensures that your fish remains moist, flavorful and vibrant.In the photo above, both salmon fillets were cooked to the same internal temperature of 48°C / 118°F. The fillet on the left was cooked sous vide (instructions below) while the fillet on the right was cooked in an oven. The difference is dramatic: the outside of the traditionally cooked salmon got too hot, causing the flesh to contract and dry out. However, the sous vide salmon retains its vibrant color, its briny juices, and produces a soft texture that is unparalleled in traditional cooking.
Basic Sous Vide Salmon Recipe
A little olive oil, a zip-top bag, and a 48°C / 118°F bath are all you need to cook a salmon fillet. Here’s how:
- Attach the Sansaire to the container of your choice, and preheat the sous vide bath to 48°C / 118°F (see below for doneness preference).
- (Optionally) remove the skin from the salmon fillet. Better yet, ask your fishmonger to do this for you when you purchase your salmon. Remove the bones. Cut the fillet into the portions you’ll end up serving – the fish will cut much cleaner when it’s raw than after it has been cooked.
- Add 1 tbsp. olive oil to a zip-top bag, then add a salmon fillet. Use the water displacement method to remove air from the bag. Bagging each fillet individually will ensure that they don’t become stuck together during cooking.
- Cook 30 minutes for a 1” thick fillet, or until the core temperature of the fish reaches to 47°C / 117°F (one degree below the bath temperature).
- Remove the salmon from the bag. Plate, and season with high-quality olive oil, flaky sea salt or any other sauces or garnishes you prefer.
How to choose the cooking temperature for sous vide salmon
The video above shows salmon cooked sous vide for 30 minutes at 5 different temperatures. Notice the dramatic difference in texture between 40°C / 104°F and 60°C / 140°F. What’s the best temperature for sous vide salmon? Well, that’s a matter of personal taste. We prefer our salmon between 45-50°C, but some folks may prefer a higher degree of doneness. For more on sous vide fish and food safety, see “Is it safe to eat fish cooked sous vide?” at the bottom of this page.
Considerations for vacuum packing fish for sous vide
Although some foods benefit from very strong vacuum packing, fish does not. Because fish is so delicate and cooks for a relatively short period of time, we recommend using a zip-top bag and the water displacement method to package fish for sous vide. Adding a small amount of oil to the bag adds extra flavor, and helps coat the fish to prevent it from oxidizing in the presence of any remaining air. If you do use a vacuum sealer, we recommend sealing on the “gentle” setting, or turning the vacuum strength down. Why should you avoid pulling a strong vacuum on fish? Contrary to popular belief, it’s not because the fish gets squished by the bag. Rather, it is because the boiling point of water drops dramatically at lower pressure – this is why water comes to a boil faster on top of a mountain that at sea level. So if the vacuum is strong enough, the water inside the fish boils, expands into vapor, and disrupts the delicate cell structure. As a result, your fillet ends up mushy and dry.
Searing fish after cooking sous vide
Searing after cooking your fish sous vide is an optional step, but can add flavor and a bit of crunch. In particular, searing the skin side of your fillet (if you kept the skin on) is a great idea – crispy fish skin is like the bacon of the sea. Just as with other post-sous vide searing techniques, you want to brown the outside of the food quickly, before the heat has time to overcook the interior. To crisp the skin on your fish after cooking sous vide, follow these steps:
- Preheat a heavy skillet (cast iron, or high-carbon steel) over high heat. Add a high smoke point oil, such as grapeseed or safflower, to coat the bottom of the skillet.
- Pat your fillets dry. Then, place them skin-side-down onto the hot skillet. Resist the urge to move them, as the skin may stick during the first moments of cooking.
- Sear for 30 seconds, or until the skin is crisp and releases from the bottom of the pan.
Note that you may also sear your fish flesh-side-down. However, particularly when cooking thin cuts, the heat from the skillet will work its way into the fish quickly, which will cause the fish to overcook. You may also use a blowtorch to sear fish after cooking sous vide, but to our taste, pan-searing produces a more flavorful result.
Can I cook fish straight from frozen?
Yes! Cooking fish sous vide straight from the freezer is highly practical, as many species of fish are sold frozen and individually vacuum packaged. However, there are a few considerations to keep in mind:
- The cooking time will be longer when starting from frozen, but how much longer is complicated to calculate. The best way to know when your fish has reached the target temperature is to use an instant-read probe thermometer to measure the temperature in the middle of the thickest part of the fish.
- Ensure that the fish was sealed in sous vide-safe plastic. If your fish came pre-packaged in vacuum-sealed bags, check that the bags are made from polyethylene or polypropylene, and are BPA-free. If not, transfer the frozen fillets to a bag made from the appropriate material.
- Don’t crowd the bath. Use a large water bath compared to the amount of food you’re cooking. Adding frozen food to the bath will cause the water temperature to temporarily dip, but the higher your ratio of water to food, the faster the temperature will recover.
Brining fish for sous vide cooking
Brining is a great way to improve the flavor and texture of fish when cooking sous vide, if you have a little extra time to prepare. The salt in the brine causes the muscle fibers in the fish to swell and retain more water. In salmon, for example, brining before cooking will also prevent albumin (the white stuff between muscle fibers) to leech out during cooking. You can create a simple brine by dissolving 5 parts salt into 100 parts cold water. Add herbs, spices or other aromatics if you prefer. Submerge your portioned salmon fillets in the brine and refrigerate for 3-5 hours. Then, drain off the brine before following the normal procedure above.
Is it safe to eat fish cooked sous vide?
Cooking fish sous vide does not pose any greater food safety risk than eating fish cooked traditionally. If anything, having an awareness of the time and temperature at which your fish is cooked actually promotes food safety! Most people prefer their fish to be lightly cooked, as fish will toughen and dry out at higher temperatures. You’ve probably seen restaurant menus disclaim “Consuming raw or unpasteurized seafood may increase your risk of foodborne illness.” To be clear, the sous vide cooking times and temperatures we suggest will not pasteurize the fish. But, neither will the FDA’s guidelines!
The chart above shows the pasteurization curve – the time and temperature combination that ensures pasteurization – when cooking sous vide. Specifically, this curve signifies the time required to pasteurize Salmonella, which is not a concern for seafood, but illustrates our point nonetheless. Any time and temperature combinations above the blue line will ensure that your food is pasteurized. Note that the FDA’s guidelines (the red dot) recommend cooking fish to 63°C / 145°F for 15 seconds. Not only will this temperature ruin the texture of the fish, but it also won’t pasteurize it! Consuming any food involves some amount of risk, but purchasing your fish from a good source and handling it properly are the best ways to keep that risk low. Some fish, like tuna, farmed salmon, swordfish, and freshwater fish are generally considered safe to eat raw, or cooked to any temperature you prefer. Other fish, including wild salmon, halibut, cod, sea bass and inshore saltwater fish are not. This second group of fish is susceptible to a parasite called an anisakid nematode (a tiny, disgusting worm). The best way to kill this parasite is to freeze and hold fish, but as most home freezers aren’t up to the task, we recommend buying fish that has been commercially flash-frozen if foodborne illness is a concern for you. It’s worth noting, however, that the FDA reports no known cases of mortality from anisakid infection.
- Modernist Cuisine at Home’s chapter on Salmon
- Modernist Cuisine Volume 1, Chapter 3: Food Safety
- United States Food and Drug Administration’s Bad Bug Book (PDF Link)
- How to remove bones from salmon (video)