-60C freezers for keeping sushi grade catch year-round

Dexter Outdoors

fishing_addict88

tuna wisher
May 16, 2014
15
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Name
Adrian Guthals
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NA
I was in the market for a freezer in preparation for my October LR trip. Almost picked up a -20C chest unit off craigslist but I wanted to look into higher end units that could potentially keep fish at sushi grade longer than 1-2 months. Given the investment I already made into vacation from family, 2-speed reels, tackle, 4k boat tickets, and fish processing fees, I figured it might be worth considering an investment into a freezer capable of keeping my catch fresh enough to enjoy some toro in April without going on another trip. Sure I can get rockfish and yellowtail year round but tuna and wahoo are "my precious"

My company develops and manufactures protein-based therapeutics thus we have to run cryogenic -80C freezers units that keep sensitive DNA/protein samples for years (residential freezers usually keep temps at -4 to -20C). Fish fillets are essentially piles of salty water with some added protein, and -20C is not cold enough to solidly freeze an entire fillet and block the molecular movement that causes oxidation within a few months - even if the catch is properly handled, vac sealed, and flash frozen. The colder you go, say -40C, -60C or -80C, the more you slow down this process. This is why high-end sushi restaurants will use -60C freezers to keep fish year round that is not otherwise available - supposedly taste-testers cant tell the difference between fresh and -60C frozen meat, but I have yet to do a taste test and am not familiar with the specifics of such a test. What convinces me is seeing protein samples come out of our -80C units at work after 1-2 years with little-to-no detectable change in oxidation or 3D molecular structure. The freeze/thaw cycle does more damage than time itself.

I spoke with Mark DuFloth at SolidCold Co. out of El Cajon, who maintains our -80C units at work and asked him for some quotes. He sells brand new Arctiko -60C chest units for $5-6k (133L to 368L capacity) with a multi-year warranty, along with -80C and -40C units (the colder, the more expensive). He also sells reconditioned units, and I ended up getting a used Arctiko SF 150 -60C model with a brand new compressor and 2-year warranty for much less. There were no conditions about promoting on BD - just sharing my experience. Mark answered all my questions:

Power Consumption: Going off of the spec sheet my 133L unit should use 100-200 kwH per month depending upon the ambient temperature of the room it is in. We have solar so no worries there

Placement: He recommends keeping the unit in a room where the temperature stays below 80F on a regular basis to keep the compressor from running 24/7. -60C is really cold (cold enough to freeze un-gloved fingers to a fish fillet), and you just can't jam enough insulation into a 2-3 inch space to keep a 80C temp gradient for very long. In a ~75F room, I am seeing the compressor run 16-18 hours per 24hr cycle which is within limits.

Longevity: Mark inspects every unit before delivery and he even modifies them to make the fan (not the compressor) run 24/7 to keep the compressor cooler. Outside of the warranty, the only thing that can really fail is the compressor which costs ~$500 to replace. He normally sees the -40C units run 10-15 years without issues as long as they are not over stressed. The -60C units are new and he has yet to have any major issues.

Use: My unit is not made to flash freeze fish so everything should be previously frozen at -20C before entering the deep freeze.

Cost: -20C units are cheap, so the added cost does not make sense for everyone, especially those with no other place to keep a freezer than a hot garage. The added cost of a -60C unit is due to the specialized gas exchangers and coolants in the compressor. I believe he also sells -40C units brand new for $500-1000 as they are more or less upgraded -20C models.

Here is Mark's website and email if you are interested. He is the president of SolidCold.

markd (at) solidcold.com
www.solidcold.com
 
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Bill W

tunaholic
  • Jan 12, 2006
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    Bill Walsh
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    A regular freezer destroys the meat texture in sushi. From 0 to -8 deg. C water crystals form in the meat. Standard sushi quality tuna are stored onboard commercial boats at -35 cent. with some markets requiring -60 C storage.

    Also sushi has parasites that can be killed with the greater cold, where just freezing takes more time to kill.
     
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    NaplesJohn

    Never Forget 343
    Jun 9, 2010
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    692
    Port Aransas, TX, USA
    Name
    John
    Boat
    Wilderness Systems T-160...and just sold the boat!!!
    I'm still eating wahoo and tuna from a fall 10 day...plenty good for me, and we eat all the tuna raw or seared with no complaints. Plus my garage gets over 90 on a routine basis in south Texas summers.
     
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    screamingreel

    Long Range Fanatic
    Jan 14, 2006
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    longrangesportfishingsandiego.com
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    Jeff Burroughs
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    Long Range and Private
    FYI: I have a - 20 C freezer and it works great! I am considering an - 80 C model, but they are $$! It should also be very effective with other types of meat.

    Decisions, decisions...

    - Jeff Burroughs
     
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    pgangler

    12Wt
    Jul 25, 2012
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    Pacific Grove, Calif
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    Ron
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    Was Cabo35, now GW Gulfstream
    Very informative post Adrian - thank you!

    One question: Why do you need to pre-freeze the fish to -20 before putting them into the deep freeze? That part isn't clear to me.
     
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    JoshInSD

    Member
    Dec 22, 2015
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    Josh
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    Mackerel Magnet (Sailfish 21' CC)
    What does a used -60c run?

    So pre-freezing in a regular freezer at 0'F would be sufficient as the is -18C?
     
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    Anglewood

    Up to no good...
    Feb 16, 2012
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    Connor
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    Intrepid, New Del Mar
    Very interesting thread! I've taken to having Five Star freeze my fish for me and then it goes straight into the chest freezer. So far, I haven't had a problem with fish up to a year an a half old, though by then most of it is either eaten or given away.

    -Connor
     
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    Fincutter

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    Oct 3, 2016
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    Bartlett, IL
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    Greg
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    Looking for a new one
    I have a chest freezer and put all of my fish at the bottom. I assume that it's colder at the bottom, but I've never measured the temperature. Regardless, my yellowtail is still grill-worthy after two years (no trips last year) but my YFT seemed to degrade after about six months.
     
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