This Fish Defrosting Method Could Be Dangerous — Here’s What Experts Recommend Instead

If you love using your sous vide machine for defrosting fish, you could be making a dangerous mistake. In a recent Instagram reel, food scientist and creator @hydroxide.foodscience explains that you should never thaw or cook frozen fish directly in its original vacuum seal packaging, “because this could introduce an extremely dangerous toxin called botulinum toxin, which causes botulism (a fatal illness that could paralyze you).” To find out how best to defrost frozen fish, we consulted the expertise of food scientist Brian Chau, who said that Clostridium botulinum spores could cause the sous vide bag to balloon — a clear indication that your fish has been contaminated.

According to Chau, fish left to thaw at room temperature is most susceptible to the growth of microbes and has the potential to produce the botulinum toxin, so the best ways to defrost fish are overnight in the refrigerator or, if you’re looking to defrost fish fast, you can use your sous vide machine — just be sure to remove the original packaging and transfer your fish into a new vacuum seal bag. Exposing the fish to oxygen can help, said Chau. “If the bag is opened and [the fish is] placed into a new bag to be vacuum sealed and sous vided, then the aeration can mitigate some risks since C. botulinum grows in conditions without oxygen.” Read on to snag the sous vide products you’ll need to get started.

Sous Vide Machines and Accessories to Buy at Amazon

• Breville Joule Turbo Sous Vide Machine, $250
• Anova Culinary Sous Vide Precision Cooker, $110
• Inkbird Sous Vide Immersion Circulator, $68 with coupon, originally $91
• Anova Culinary Sous Vide Precision Cooker Nano 2.0, $79
• Firawer Reusable Sous Vide Bags, Set of 20, $10, originally $12
• Everie Sous Vide Container, $35
• Tongass Sous Vide Magnets, 8-Pack, $21

Breville Joule Turbo Sous Vide Machine

This test-winning sous vide machine blew us away with its user-friendliness. The Breville Joule is controlled solely via an app on your smartphone, so the machine itself is as minimalist as it gets. It’s not only easy to set up, but the app guides you through the steps each time you cook, making it a beginner-friendly option. It comes with an industrial-strength magnet to keep your sous vide machine firmly attached to the side of your container.

Anova Culinary Sous Vide Precision Cooker

The Anova Culinary sous vide machine was the second-best model our editors tested. The immersion cooker is Wi-Fi-enabled and easy to control using a smartphone app, but it also has onboard controls that come in handy when you don’t have your phone nearby. With nearly 10,000 five-star ratings from happy shoppers, the machine is an Amazon bestseller, and it’s less than half the price of our top pick from Breville.

Inkbird Sous Vide Immersion Circulator

Our favorite sous vide machine for beginners is currently on sale at Amazon. While it takes a bit longer to heat up than its competitors, the Inkbird immersion cooker comes at an approachable price point and is relatively easy to use. 

Anova Culinary Sous Vide Precision Cooker Nano 2.0

With over 12,300 perfect ratings at Amazon, this sous vide machine from Anova is a fan-favorite for good reason. The handheld gadget is small enough to store in most kitchen cabinets but is shockingly powerful with a wattage of 750 and a 3,000-hour continuous run time.

Firawer Reusable Sous Vide Bags, Set of 20

If you plan on using your sous vide machine to defrost fish, you’ll need plenty of extra bags to keep it toxin-free. These bags are a wallet- and environmentally-friendly option, since they can be reused up to 10 times. They have resealable double zippers that lock in freshness and keep moisture from entering the bag. The set comes with two sealing clips and five air valves for seamless vacuum sealing.

Everie Sous Vide Container

If you’re new to the world of sous vide, you’ll need the right container to get started. This 12-quart container is a great choice. It has a hinged lid that lets you easily refill your water or check on your food without disturbing the cooking process, and there’s a small hole at the top to hold your sous vide machine.

Tongass Sous Vide Magnets, 8-Pack

These magnets are a clever way to keep your sous vide bags from floating to the top during the cooking or defrosting process. The powerful silicone-coated ceramic magnets keep bags in place, ensuring your food remains fully submerged. As a bonus, they work with almost any bags and containers.