As a seafood lover and avid fisherman, I’m always looking for the best ways to preserve my catch so I can enjoy it for months to come. Flash freezing is one of the most effective methods for retaining flavor and texture. But exactly how long does the flash freezing process take? In this article, we’ll take a deep dive into flash freezing times for fish.
What is Flash Freezing?
Flash freezing also known as blast freezing or cryogenic freezing is an ultra-fast method of freezing fish. It involves bringing the temperature down incredibly quickly, freezing the fish solid in just a few hours. This rapid freezing minimizes ice crystal formation and cell damage.
The key is to freeze the fish as soon as possible after catching it. Fish should ideally be flash frozen within 3-4 hours of being caught. This helps lock in freshness and quality.
Flash freezing can be done in two main ways:
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Dry ice or liquid nitrogen immersion The fish is submerged directly into dry ice (-70°C/-94°F) or liquid nitrogen (-196°C/-320°F). This instantly brings the temperature way down
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Flash freeze refrigerator The fish is placed into a specialized blast chiller unit that blasts it with freezing air, Temperatures reach anywhere from -30°C to -40°C (-22°F to -40°F)
Both methods can freeze fish solid within 1-2 hours when done correctly. Let’s look at freeze times for each process in more detail.
How Long Does Dry Ice Immersion Take to Freeze Fish?
Using dry ice is the most accessible and cost-effective way to flash freeze fish at home. Here are the approximate dry ice immersion times needed to fully freeze different fish cuts:
- Fillet pieces: 30-60 minutes
- Whole fish < 5 lbs: 1-2 hours
- Whole fish > 10 lbs: 3+ hours
The freezing time depends on a few factors:
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Thickness of the fish: Thicker cuts take longer to reach core temperature. Fillet the fish into smaller, thinner portions if possible.
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Surface area: Fish pieces stacked together will freeze slower than fish spread out in a single layer.
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Insulation: Use a cooler with 2-3 inches of insulation for dry ice immersion. Thin coolers cause temperature fluctuations and slow the process.
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Fish to ice ratio: Use at least 2-3x as much dry ice as fish by weight. More dry ice means faster freezing.
With the right dry ice setup and technique, most fish portions can be frozen solid within 1 hour or less.
How Fast Do Commercial Flash Freezers Work?
Commercial blast freezer units are extremely powerful, generating temperatures from -30°C to -40°C. They can flash freeze fish much faster than home methods:
- Whole fish < 2 lbs: 30-45 minutes
- Fillet pieces: 45-60 minutes
- Whole salmon: 1-2 hours
- Large tuna: 1.5-3 hours
The freeze time varies based on the specific blast freezer model, air flow, and how tightly fish is packed together. But most commercial units freeze fish solid under 3 hours.
Some high-end units even have conveyor belts continuously moving product through the freezer. This exposes fish to freezing temperatures on all sides, reducing freeze times even further.
What If I Don’t Have a Blast Freezer?
While commercial blast freezers are ideal, you can still successfully flash freeze fish without one:
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Use dry ice: Follow the dry ice immersion method outlined above. Have enough ice and insulated cooler space to work in batches.
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Crank the home freezer temp: Get your freezer as cold as possible, ideally -30°C/-22°F or below. The colder it is, the faster the freeze.
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Freeze small batches: Don’t overfill the freezer. Freeze fish in single layers with space between pieces.
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Pre-chill fish: Place fish in the fridge or on ice first to drop its temp before freezing. Colder starting temp means faster freeze.
With these tips, you can still achieve freeze times under 2-3 hours at home – not as fast as commercial blast freezers but much better than a typical 24+ hour freeze.
How Long Does Frozen Fish Last After Flash Freezing?
The beauty of flash freezing is that it retains quality for a very long shelf life. Here are the approximate freezer times for flash frozen fish stored at -18°C/0°F or colder:
- Lean fish like cod: 12 months
- Fatty fish like salmon: 9-12 months
- Shellfish like shrimp: 12 months
- Oily fish like tuna: 15-18 months
Proper handling is important for maximizing shelf life. Make sure to seal fish in airtight packaging with all air pressed out. Use high-quality, freezer-grade packaging like vacuum seal bags. Store fish in a consistent temperature freezer.
With optimal freezing and storage, flash frozen seafood can last up to 2 years while still tasting incredibly fresh and flavorful!
Flash Freeze Fish in 5 Simple Steps
If you want to flash freeze your catch at home, follow these steps:
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Fillet the fish and cut into portions about 4-6 oz each. Go as thin as possible.
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Vacuum seal the portions to remove air and prevent freezer burn.
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Place sealed fish packs directly into dry ice cooler, spacing them in a single layer.
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Pour ice water into the cooler to submerge packs. Use enough dry ice to keep temperature at -70°C/-94°F.
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Agitate packs occasionally. Remove and transfer to freezer once fully frozen solid, about 1 hour.
And that’s all there is to it! With the right technique, you can lock in fresh seafood taste at home with DIY flash freezing.
Mastering the Thawing Process
Proper thawing is also crucial for flash frozen seafood. Here are some tips:
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For best quality, thaw overnight in the fridge at 2-3°C/35-38°F.
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You can also submerge sealed bags in cold water until thawed. Change water every 30 mins to keep it cold.
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Microwave thawing is high risk for uneven temps and cooking edges. Avoid if possible.
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Cook fish immediately after it’s thawed, don’t refreeze. Refreezing causes significant quality loss.
Take the time to thaw slowly and gently. This preserves the quality fish texture and moisture content. Follow these best practices, and your flash frozen catch will be amazing for the next seafood dinner!
The Bottom Line
So how long does it really take to flash freeze fish? With the right methods and equipment, most fish can be frozen solid within 1-3 hours. Quick freeze times like this lock in freshness and minimize damage from large ice crystals. Both at-home and commercial flash freezing allow you to enjoy incredibly high-quality frozen seafood for months into the future.
What Does Flash Frozen Mean? Is It Really Fresh?
We all want to feel good about the seafood we serve our families. We want items that are nutritious, flavorful, high-quality, and safe to eat. For many people, this means favoring fresh over frozen seafood – if they’ll buy frozen items at all.
Believe it or not, fresh and frozen don’t have to be enemies. In fact, they don’t even have to be opposites!.
Flash freezing is a new technology-based process that takes the best parts of both fresh and frozen seafood and puts them together to make high-quality seafood products. Without the use of artificial preservatives, flash-frozen foods stay fresh longer, making it a healthy and environmentally friendly way to enjoy your favorite seafood at its best.
What Is Flash Freezing?
Flash freezing is a modern freezing process that uses cryogenic temperatures to freeze products at an accelerated rate. High-speed, very cold air is pushed across a product using advanced technology to freeze it solid as quickly as possible. Most products are then immediately vacuum-sealed to maintain this status until they are defrosted. This results in frozen items that, when thawed, are just as fresh as the day they were frozen.
Flash freezing is widely used across the seafood industry to preserve shrimp, scallops, fish, and more. Almost all commercial fishermen immediately flash-freeze their catch after cleaning to lock in flavor and preserve shelf-life. In fact, the FDA says that any fish that is meant to be eaten raw must be put in a deep freezer at temperatures below zero for a long time to kill any parasites and make the fish safe to eat.
What is the difference between flash frozen and frozen?
Don’t let the name fool you – flash-freezing is much different than what happens in your household freezer. It’s done much faster, at much colder temperatures, and takes much less time than traditional freezing. It also has far better results!.
Have you ever seen that icy buildup on some frozen meats? That’s made of ice crystals, which form when food is frozen slowly at temperatures close to freezing point, which is what a regular freezer does.
When these crystals thaw, they break down tissue fibers and remove water from meat, giving it a stale, watery taste.
In contrast, flash-freezing uses cryogenic temperatures to freeze meats in a matter of minutes. This means that those harmful ice crystals don’t have as much time to form on your seafood, so it’s safer and of higher quality.
- Manage seasonal changes in volume and supply
- Regulate the high cost of distribution
- Allows for a slower transport that uses less emissions
- Deal with the high amounts of seafood waste (about 93 percent of the seafood bought by stores ends up in the trash!)
- Tackle the unaffordable nature of seafood products for consumers
Sustainable fisheries management is hard to do when the seafood market is known for being unstable, with prices, variables, and demand changing all the time. Fishing for different types of fish, in different weather, and outside of fishing season (when prices or demand might be higher) are all made possible by being able to store and sell frozen food for a longer period of time.
What are the benefits of flash-freezing?
Flash-freezing has a number of benefits that make it better for consumers, the seafood community, and the environment:
Like an ice cube melting in water, fresh seafood starts to lose its quality as soon as it comes into contact with air. Flash-freezing at sea captures fish in their freshest state to preserve the ideal taste, texture, nutrients and appearance. In fact, flash-frozen fish are virtually indistinguishable from a same-day catch!.
The ultra-low temperatures used in flash-freezing effectively kills harmful bacteria. In fact, the FDA requires that fish intended for raw consumption – those used in dishes like sushi or ceviche – must be frozen first to kill parasites.
Fish that are flash-frozen and vacuum sealed can maintain their freshness indefinitely. This means buyers can fill their own freezers with all of their favorites and never stress about spoiling!.
Flash-freezing keeps seafood prices affordable by cutting down on shipping costs. Businesses don’t have to rent expensive planes to quickly move fresh goods; they can choose longer, less expensive ways to get them there. It also means businesses can affordably ship species to non-native locations, saving you money on your far-away favorites.
Money isn’t the only reason easy shipping options are a big benefit for flash-freezing. Transporting a flash-frozen product by boat, train, etc. produces far less carbon emissions than flying a fresh product across the same distance. The ability to reduce carbon emissions is a major win for sustainability.
A staggering amount of fresh food products are wasted by retailers each year. Stores have to get rid of fresh goods that aren’t bought within a few days of being put on the shelves. Flash-frozen foods, on the other hand, can be kept for a lot longer or even sent to other places to reduce food waste.
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How To Freeze Fish at Home | A Fishmonger’s Guide
What is flash freezing fish?
Flash freezing is an accelerated process of storing fresh food within 24 hours of its harvest. For fish, flash freezing needs to be done almost immediately. Author Note: This process is done with either dry ice at -70℉ or liquid nitrogen at -320℉. Most commonly, dry ice is the way to go. It’s easier to handle and buy. Why Flash Freeze Fish?
How long does flash frozen fish last?
Flash-frozen food should last just as long as any other frozen items in your freezer. How do you flash freeze fish at home? To flash freeze fish at home, place each individual piece of raw fish on a baking tray. Put that tray into your freezer and allow each piece to freeze.
What happens if you flash freeze fish?
So that’ll rupture cell walls and cause loss of texture, a fishy taste, all those problems,” Tracy said. “But when you flash freeze it, you freeze it super cold and super fast.” Flash freezing means a fish can go from the water to the boat to being fully frozen in a matter of hours. Once it’s flash-frozen, it keeps fine in a regular home freezer.
How long does it take to freeze fish?
Depending on the fish-to-ice ratio and efficiency of the cooler, it could take from 5 to 12 hours to finish freezing. Move the portions into their permanent storage at -10℉ or cooler. Keep in mind that the better your freezer is, the higher quality of fish you’ll maintain for longer.