Flash freezing fish (tuna, escolar and moonfish) with dry ice

[Dima]

So last week I finally made it out to the Tuna Harbor Dockside Market and picked up some Ahi, Albacore, Opah and Escolar fillets. I love sashimi and poke but I know it's not recommended to eat raw fish because there is a risk of food poisoning or contracting a parasite.
Basically it has to be frozen prior to consumption. If you just throw it in the freezer it freezes very slow causing the ice crystals to damage the meat, destroying the quality.
The best way to do it is flash (or blast) freezing but those type of freezers are expensive. So I decided to do it on my own using dry ice and alcohol

Basically I had the fish cut into smaller size fillets and then sealed them using the vacuum sealer.
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It's best to use food grade alcohol (like ethyl) but since it wasn't available at the time I used the isopropyl instead.
It has to be 80% (160 proof) or more else the liquid itself is going to start freezing.
Be sure it does not get into your food!
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I've picked up some dry ice from Vons, $2/lb, I got 10lb for my 20lb of fish
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Added the alcohol into a metal pot
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[Dima]

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Slowly added some pieces of dry ice. It's best to make the pieces the size of a golf ball or so and add them slow so the liquid doesn't boil over the top
Dry ice is very cold and will burn your skin almost instantly so handle with care!
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I used a laser thermometer to measure the temperature.
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You want it to be below 30F (30C) before you start putting the fish in.
This extremely cold liquid can be dangerous, avoid any contact with skin!
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[Dima]

Once the temperature dropped below 30-35F I added few more pieces of dry ice and started putting the fish in
I kept monitoring the temperature so when it went above 30F I just added some more ice
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I left the fish sitting there for about 10-15 minutes
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Once they are fully frozen I took the packets out, quickly rinsed them and placed them in the freezer.

[Dima]

When you're ready to eat your fish, just put the packets into a room temperature water for about an hour and it's ready to go!
The sashimi came out excellent, as fresh as it gets.

P.S. Don't try this at home

[Neuroshima]

Thanks for the instructions. For those who try this, make sure you're in a well ventilated area, or you can pass out from the CO2.

[maraxus]

Thanks for the detailed instructions. You've gone to great lengths to ensure highest quality! Pretty impressive!

[Dima]

Thanks for the detailed instructions. You've gone to great lengths to ensure highest quality! Pretty impressive!

That's what happens when a person has too much time on their hands
I should have just went to H-Mart and bought me some sashimi grade fish

[postboxtrapdoor]

Flash freezing fish with dry ice is a rapid and effective method to preserve the freshness and quality of seafood, including tuna, escolar, and moonfish. This technique involves using dry ice, which is solid carbon dioxide, to quickly lower the temperature of the fish to extremely cold levels.

Flash freezing with dry ice is a valuable technique for commercial fisheries, seafood processors, and even home chefs looking to lock in the freshness of their catch. It's essential to follow safety guidelines when handling dry ice and to adhere to proper storage and thawing practices for the best results.

Thank you.