Properly Defrosting Cryovacked Fish

[audreyh1]

(OK - this is an obscure one for us retirees with lots of "time" on our hands, who enjoy eating great at home because we have time to do a nice job.)

I prefer to buy my fish frozen if it is not sourced locally. Ideally it will have been frozen very soon after harvest for optimal freshness. It then goes in my freezer until a couple of days before I am ready to use it. If I buy "fresh" fish at the seafood counter, I don't know how long it took to get to the store, or how long it has been sitting around, and then I feel pressure to cook it as soon as I get home. I don't think it is particularly "fresh" at that point unless I know it has been harvested along the Texas Gulf Coast. Your store may be able to tell you when the fish was harvested.

In many cases, commercial freezing kills parasites, so I can also minimally cook the fish if I choose to without worry. If a fish has never been frozen I feel compelled to cook it to the temps required to kill the parasites. For salmon, never frozen fish must be cooked to 145° internal temp for 15 secs to kill nematodes. Almost all sushi fish served raw in the US is supposed to be flash frozen per FDA regs, just in case you wondered. Tuna is one exception as it doesn't pose a parasite risk to humans.

I like it even better if I can buy it frozen in the original packaging. If a store offers previously frozen fish in their display counter, I look for the same thing in the freezer section. In many cases this is a "Cryovac" package - where I think the fish is packaged in a vacuum (removal of air) after it is frozen solid. This prevents freezer burn as well as inhibiting bacterial growth.

I've noticed that these packages often have thawing instructions that include breaking the seal on the package (releasing the vacuum) or removing the fish from the package completely before thawing. I didn't understand at first why this might be important.

The main reason the package has such instructions is probably because botulism bacteria can grow in an an anaerobic (no oxygen) environment, and so it is certainly advised not to allow foods in a vacuum to thaw slowly at room temperature, and this is perhaps extended not to allowing the food to thaw slowly in a vacuum in the fridge, even though cold fridge temperatures (below 40°) should be enough to inhibit growth of this dangerous bacteria.

Another reason to do it may be the affect on the texture of the raw fish under vacuum when thawing. I have read some comments that indicated "excess moisture" would be drawn out of the fish if left in the sealed package to defrost, that the texture of the fish was suboptimal, or even that the fish gets a little smellier.

Anyway - this last time I was careful to follow the package instructions on a side of sockeye salmon from Trident foods in the original packaging. The instructions were to poke some holes in the package and then to let thaw meat (not skin) side down. I made sure part of the package lifted from the fish so that air could get in while it was defrosting and left it to defrost in the fridge for a couple of days.

I do think less moisture was drawn out of the raw salmon. The texture was excellent, and there was very little smell. It did appear to be better than last time when I didn't break the seal. Last time the fish was fine, but this is definitely better.

Next - I'll be defrosting some ahi tuna which I plan to pan sear and eat partially raw. Some people have complained about cryovacked tuna getting smelly after defrosting, or that the smell problem was because it shouldn't be left to thaw in it's own juices. Hopefully if I take the right precautions my frozen tuna will be nice after defrosting.

 

[audreyh1]

I really didn't realize I was going to write an essay. I know from the "Who needs to eat out!" thread that folks here are quite particular with their food preparation.

 

[Sue J]

I also buy some of my fish frozen in cryovac packs. Or I buy fresh on sale and cook some and freeze some. I have a Foodsaver vacuum sealer so it's comparable to the cryovac packs in the store.

I defrost these things in a sink full of cold water. Do not puncture the plastic wrap. Thin pieces will thaw in maybe 30-45 minutes, thicker ones in maybe 1.5 hours. I try to remember to change the water at least once if it's taking a long time. I find this a very gentle thawing method, much faster than overnight in the refrigerator.

I open the package when it's thawed or even still a little frozen, rinse and pat dry and then cook.

Am I doing anything wrong defrosting the still sealed vacuumed package in cold water?

 

[kaneohe]

Audrey.........thanks for the educational essay.....didn't know that.

 

[harley]

Of course, I've been doing everything wrong for decades and haven't died yet. Although I might try to do it right and see if the flavor and texture are better. Thanks for the info.

 

[MRG]

...snip...

In many cases, commercial freezing kills parasites, so I can also minimally cook the fish if I choose to without worry. If a fish has never been frozen I feel compelled to cook it to the temps required to kill the parasites. For salmon, never frozen fish must be cooked to 145° internal temp for 15 secs to kill nematodes. Almost all sushi fish served raw in the US is flash frozen per FDA regs, just in case you wondered. Tuna is one exception as it doesn't pose a parasite risk to humans.

..snip..

Next - I'll be defrosting some ahi tuna which I plan to pan sear and eat partially raw.

Thank you for confirming that. It's what I thought, but I wanted confirmation. My knife skills work just fine for some nice sushima. Maybe nigiri or Ceviche.

 

[audreyh1]

I also buy some of my fish frozen in cryovac packs. Or I buy fresh on sale and cook some and freeze some. I have a Foodsaver vacuum sealer so it's comparable to the cryovac packs in the store.

I defrost these things in a sink full of cold water. Do not puncture the plastic wrap. Thin pieces will thaw in maybe 30-45 minutes, thicker ones in maybe 1.5 hours. I try to remember to change the water at least once if it's taking a long time. I find this a very gentle thawing method, much faster than overnight in the refrigerator.

I open the package when it's thawed or even still a little frozen, rinse and pat dry and then cook.

Am I doing anything wrong defrosting the still sealed vacuumed package in cold water?

The fast defrost may avoid bacteria issues as long as it is then cooked immediately - although I'm not an expert.

It might be worth trying without vacuum to see if there is any improvement in smell and texture. Put in a different bag before thawing?

 

[Payin-the-Toll]

Dang, suddenly I'm not hungry for fish!

 

[audreyh1]

I should have said in the US the sushi raw fish is supposed to be flash frozen sufficiently to kill parasites, so it comes down to how much you trust your sushi food suppliers.

 

[MRG]

Thanks. I get your point.

 

[haha]

Nice explanation. Much (maybe all) Trader Joe Fish is packed this way. I have been thawing this way for while, since the packaging recommends this method. I never understood why, I just figured that they knew more about it than I did.

It seems good, but I cannot seem to get it up to the quality of never frozen fresh fish brought home and cooked.

Some months ago I gave up trying to decide whether fish oil was a good thing or a bad thing for a man's sexual health, so I switched over to a can a day (~5 cans/wk) of King Oscar Norwegian Brisling for any Omega 3 benefits. I love these things, and I eat them whether I am having fish for dinner or not. No such thing as a dry King Oscar. Years ago I bought them in cases from Costco. Now I have an Amazon standing order.

Ha

 

[audreyh1]

If I lived in the Pacific NW, I would enjoy having access to fresh salmon and halibut and numerous other items.

Here we have awesome shrimp and nice red snapper and drum and flounder. That's about it.

Can't complain about our access to high quality fresh shrimp.

Costco carries quite a bit of fresh fish from the Pacific NW when it's in season. I even saw halibut the other day. They give the date when packaged. I need to ask the people behind the counter how quickly they get their fresh fish.

 

[imoldernu]

We hardly ever eat fish any more. Spoiled rotten by living the first forty years in Pawtucket, Brunswick, Falmouth, Vineyard Haven and other towns in New England, where the fish was always off-the-boat fresh.

A time when fish was for "poor people" and we qualified. Anyone who knows what schrod is, without looking it up, is old enough to remember. A time when swordfish was $.25/lb. (sigh)

 

[audreyh1]

We hardly ever eat fish any more. Spoiled rotten by living the first forty years in Pawtucket, Brunswick, Falmouth, Vineyard Haven and other towns in New England, where the fish was always off-the-boat fresh.

A time when fish was for "poor people" and we qualified. Anyone who knows what schrod is, without looking it up, is old enough to remember. A time when swordfish was $.25/lb. (sigh)

Your avatar indicates you should be eating a diet of seal!

 

[walkinwood]

Thank you - I'm going to try it the next time. Thankful that I haven't succumbed to botulism quite yet.

 

[audreyh1]

IMO (uneducated opinion), defrosting by laying the vacuumed package on the counter in a warm room all day could run a botulism risk. Hopefully no one here does that.

We don't hear news stories about botulism poisoning, do we? Well, other than botox shots for wrinkles.

In the United States, an average of 145 cases are reported each year.Of these, approximately 15% are foodborne, 65% are infant botulism, and 20% are wound. Adult intestinal colonization and iatrogenic botulism also occur, but rarely. Outbreaks of foodborne botulism involving two or more persons occur most years and are usually caused by home-canned foods. Most wound botulism cases are associated with black-tar heroin injection, especially in California.

from CDC - Botulism, General Information - NCZVED

I'm curious to see if people notice an improvement in quality of texture or a fresher smell when they break the seal on a cryovac package before defrosting.

 

[springnr]

One possible problem to be aware of in Sous Vide (under pressure, vacuum) cooking; there is a potential for food poisoning when food is stored after cooking.
================================
DouglasBaldwin.com
Table of contents

• Pathogens of Interest

For cook-chill sous vide, Listeria monocytogenes and the spore forming pathogenic bacteria are our pathogens of interest. That’s because Listeria is the most heat resistant non-spore forming pathogen and can grow at refrigerator temperatures (Nyati, 2000b; Rybka-Rodgers, 2001), but appears to require more bacteria to make you sick than Salmonella or E. coli. Most experts recommend a 6 decimal reduction in Listeria if you don’t know the contamination level of your food.

While keeping your food sealed in plastic pouches prevents recontamination after cooking, spores of Clostridium botulinum, C. perfringens, and B. cereus can all survive the mild heat treatment of pasteurization. Therefore, after rapid chilling, the food must either be frozen or held at

1. below 36.5°F (2.5°C) for up to 90 days,
2. below 38°F (3.3°C) for less than 31 days,
3. below 41°F (5°C) for less than 10 days, or
4. below 44.5°F (7°C) for less than 5 days

to prevent spores of non-proteolytic C. botulinum from outgrowing and producing deadly neurotoxin (Gould, 1999; Peck, 1997).

 

[audreyh1]

Blue Bell ice cream just shut down their Oklahoma plant due to deaths from listeria in Kansas. Our local stores are pulling their products from the shelves.

 

[harley]

Nice explanation. Much (maybe all) Trader Joe Fish is packed this way. I have been thawing this way for while, since the packaging recommends this method. I never understood why, I just figured that they knew more about it than I did.

It seems good, but I cannot seem to get it up to the quality of never frozen fresh fish brought home and cooked.

Some months ago I gave up trying to decide whether fish oil was a good thing or a bad thing for a man's sexual health, so I switched over to a can a day (~5 cans/wk) of King Oscar Norwegian Brisling for any Omega 3 benefits. I love these things, and I eat them whether I am having fish for dinner or not. No such thing as a dry King Oscar. Years ago I bought them in cases from Costco. Now I have an Amazon standing order.

Ha

Wow! Not cheap at $3/tin, even in bulk and on a subscription. I love sardines and may give these a try, but I tend to shop the sales for them. I especially like the beyond-the-sales-date stores, since I don't think these things would go bad in less than a decade. I eat them for breakfast at times, although it makes DW gag.

 

[haha]

Wow! Not cheap at $3/tin, even in bulk and on a subscription. I love sardines and may give these a try, but I tend to shop the sales for them. I especially like the beyond-the-sales-date stores, since I don't think these things would go bad in less than a decade. I eat them for breakfast at times, although it makes DW gag.

You are right, not cheap, and this sort of thing is why I don't eat for $150/month. I just can't convince myself that it is possible that I could eat myself into poverty, so I don't stress about it. I also eat $22/# halibut, and pretty much anything else that I might want.

I eat them for breakfast also, or at times mid-morning Nice cup of $20/# coffee, a tin of sardines and a bit of Trader Joe yellow mustard and dawn shows promise for me.

Afterward, I might be ready for my $5.49/12oz bacon and $3.98/dozen eggs. If I don't eat them somebody else will, and quite possibly he will be less deserving than I.

I have tried those single layer so called sardines that are much cheaper, but I could not keep eating these. They are just awful.

Ha

 

[DayDreaming]

I usually have bags of frozen salmon and cod in the freezer. I love the convenience of the vacuum packed individual portions, but I never like the texture of the fish after cooking. When I follow the thawing directions, the cooked fish usually seems kind of mushy.

I recently tried a different method - cooking the frozen fillet without thawing first. I forget where I read about doing this, and it seemed like a bad idea but I gave it a try and like the results. Take the fish out of it's plastic packaging, rinse under running tap water just to melt any icy coating that may be on the fish, pat dry, then directly into the pan. (Plus oil and season according to the recipe of course.)

One recipe I like making is first I sautee a variety of vegetables in a pan, when they're nearly done, I add the frozen fish to the pan, put the lid on, turn the flame down to low and it's usually done in about 5 minutes. I don't know why this works but I like the results much better than when I follow the package's thawing instructions.

 

[donheff]

I get a lot of frozen fillets and frozen shrimp at Costco. Like a few others I toss it in a sink full of cold water to thaw. I even use warm water if I am in a rush. I have even done this with frozen steaks in zip lock bags. Tastes fine to me. I suspect the thawing instructions are intended to keep people from tossing the packages on the kitchen counter at room temps for many hours.

 

[ERD50]

I wonder if removing from the package is to avoid the vacuum from damaging the meat as it thaws? Freeze/thaw does tend to break down cell structure, so maybe at that point, the vacuum does more damage?

-ERD50

 

[audreyh1]

I wonder if removing from the package is to avoid the vacuum from damaging the meat as it thaws? Freeze/thaw does tend to break down cell structure, so maybe at that point, the vacuum does more damage?

-ERD50

That's exactly what I think. If pressure is being put on the flesh during thawing that might explain extra liquid in the package as some people report. It also might compromise the texture. This is the main reason I am taking this step.

Some people claim that the defrosted fish sitting in those "juices" makes it smellier. They were talking about tuna specifically in that case.

Some folks take the fish out of the package and put in on something where any liquid will drain off the fish while defrosting in the fridge instead of remaining in contact with the flesh.

These are precautions worth trying to see if they do improve the quality of the defrosted fish. I haven't taken the extra step of putting the fish on something that can drain away the liquid, but if I'm not happy with my defrosted tuna, I will try that too.