# How seriously should I take this warning about defrosting vacuum-sealed fish? **URL:** \ **Category:** Cafe Society\ **Tags:** food-cooking\ **Created:** [July 21, 2026, 2:09pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827 "2026-07-21T14:09:47Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![solost](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/solost/32/11776_2.png) [@solost](https://boards.straightdope.com/u/solost)\ **Post date:** [July 21, 2026, 2:09pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/1 "2026-07-21T14:09:47Z")
So, I often get videos from this food scientist in my YouTube feed. She seems like she really knows her stuff, and I like how she makes no-nonsense videos that cut through all the BS and myths of food quality and safety. But this video kind of caught me by surprise: she basically says that if you buy vacuum-sealed fish, DO NOT sous vide or thaw it in the vacuum-sealed package it comes in, due to the risk of botulism poisoning, since the fish is in an anaerobic environment. She advises to take it out of the package still frozen, so it is exposed to oxygen, and re-seal it before sous viding or thawing. So, I don’t sous vide, but I have often in the past bought fish filets individually sealed in those vacuum-sealed packs, and many, many times have I put them in cool water to thaw before cooking. Never had a problem. It’s not like it takes that long to thaw the fish-- maybe 20 minutes tops. Is that _ **really** _ enough time for botulism toxin to form? Is it possible she’s being a little overly cautious here? In light of the possible consequences, I suppose you can’t be too careful, but still… [![](https://img.youtube.com/vi/BcGpOjm3iSo/maxresdefault.jpg "NEVER make this mistake when preparing fish! #foodscience #foodscientist") ](https://www.youtube.com/watch?v=BcGpOjm3iSo) ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [July 21, 2026, 2:26pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/2 "2026-07-21T14:26:07Z")
ISTM that if the risk was statistically significant, there’d be a lot of deaths reported. Since there are not, the risk must be statistically insignificant. Decent bet substantially _every_ portion of vacuum-packed frozen fish is thawed in the sealed pouch. In restaurants and at home. That’s millions of pounds per year in the USA alone. Where is the wide swath of botulism-killed fish eaters? They evidently don’t exist. > [@solost](#): > > In light of the possible consequences, I suppose you can’t be too careful, but still… That logic suggests one should never cross the street and definitely never drive. In light of the possible consequences … It’s a common rhetorical device and a common heuristic shortcut in thinking. But it amounts to nonsense catastrophising. Doesn’t mean it’s not a popular way to think. ---
**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\ **Post date:** [July 21, 2026, 2:31pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/3 "2026-07-21T14:31:54Z")
Usually the vacuum-packed fish has instructions for cooking it frozen or thawed. If frozen, it just has you leave it in the oven for a few more minutes. If you’re worried about thawing it, just cook it straight from the freezer. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [July 21, 2026, 2:33pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/4 "2026-07-21T14:33:29Z")
I imagine that few people are going to conventionally cook the fish in the plastic vacuum package, so the only ones who might face this issue are those who plan to use the sous vide method. ---
**Author:** ![AlsoNamedBort](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alsonamedbort/32/3213_2.png) [@AlsoNamedBort](https://boards.straightdope.com/u/AlsoNamedBort)\ **Post date:** [July 21, 2026, 2:35pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/5 "2026-07-21T14:35:39Z")
Regardless of botulism concerns, it’s usually recommended not to sous vide in the manufacturer’s packaging since you don’t know if the plastic and seal are meant for high temps. ---
**Author:** ![HoneyBadgerDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/honeybadgerdc/32/1033_2.png) [@HoneyBadgerDC](https://boards.straightdope.com/u/HoneyBadgerDC)\ **Post date:** [July 21, 2026, 2:41pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/6 "2026-07-21T14:41:39Z")
Temps for salmon are only about 132 degrees, depending on how you like it. I do it routinely. ---
**Author:** ![solost](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/solost/32/11776_2.png) [@solost](https://boards.straightdope.com/u/solost)\ **Post date:** [July 21, 2026, 2:41pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/7 "2026-07-21T14:41:52Z")
> [@LSLGuy](#): > > Decent bet substantially _every_ portion of vacuum-packed frozen fish is thawed in the sealed pouch. In restaurants and at home. That’s millions of pounds per year in the USA alone. Where is the wide swath of botulism-killed fish eaters? They evidently don’t exist. Good point. > [@LSLGuy](#): > > > [@solost](#): > > > > In light of the possible consequences, I suppose you can’t be too careful, but still… > > That logic suggests one should never cross the street and definitely never drive. In light of the possible consequences … I don’t know if that’s quite a valid comparison. Crossing a street or driving is a calculated risk mitigated by paying attention and using ones’ eyes and ears. There’s no way to know or detect which fish may have the botulimin or whether the way you cooked or thawed the fish caused the condition to form. So the equivalent comparison might be more like crossing a not very busy street blindfolded and wearing earplugs. > [@LSLGuy](#): > > It’s a common rhetorical device and a common heuristic shortcut in thinking. But it amounts to nonsense catastrophising. Doesn’t mean it’s not a popular way to think. See, that’s the thing with this person’s videos. She commonly _debunks_ myths spreading popular ideas that scare-monger or catastrophise about the so-called danger of our food supply. That’s why I’m posting here asking about this particular video. She has built up some trust with me through her typically common sense videos, but I trust the opinion of Dopers here more than anybody posting on YouTube. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [July 21, 2026, 2:50pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/8 "2026-07-21T14:50:31Z")
AIUI the vid’s contention is that this workflow risks botulism: 1. Thaw fish in factory vacuum sealed package. 2. Remove fish from factory vacuum sealed package. 3. Cook thawed fish however you want. Separately, my contention is that this workflow describes how the vast majority of such vacuum packed fish is cooked. ---
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [July 21, 2026, 2:52pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/9 "2026-07-21T14:52:39Z")
> [@solost](#): > > So, I often get videos from this food scientist in my YouTube feed. I’m highly suspicious of any Influencer who calls him or herself an “expert”. Even if the person is knowledgeable to a certain extent, the desire for clicks/followers/sponsors and thus money can often cause them to exaggerate and overdramatize in an effort to gain more attention. I think this is one of those cases. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [July 21, 2026, 3:01pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/10 "2026-07-21T15:01:20Z")
> [@AlsoNamedBort](#): > > Regardless of botulism concerns, it’s usually recommended not to sous vide in the manufacturer’s packaging since you don’t know if the plastic and seal are meant for high temps. That’s true as well. ---
**Author:** ![abcdefghij](https://avatars.discourse-cdn.com/v4/letter/a/43a26b/32.png) [@abcdefghij](https://boards.straightdope.com/u/abcdefghij)\ **Post date:** [July 21, 2026, 3:03pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/11 "2026-07-21T15:03:11Z")
> [@LSLGuy](#): > > ISTM that if the risk was statistically significant, there’d be a lot of deaths reported. I’ve learned to be careful with that reasoning. When my wife was pregnant with our daughter, there was much concern about the risk of listeria from soft cheeses and sliced meats. My attitude was basically “if the risk was statistically significant, there’d be lots of deaths reported”. Turns out, the primary risk is miscarriage. Those don’t get reported and don’t get tracked by the CDC, FDA, USDA or anybody else (even back when any of those agencies tracked anything). For my wife, it was an easy thing to give up to avoid an unnecessary risk. ---
**Author:** ![solost](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/solost/32/11776_2.png) [@solost](https://boards.straightdope.com/u/solost)\ **Post date:** [July 21, 2026, 3:17pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/12 "2026-07-21T15:17:08Z")
> [@Jasmine](#): > > I’m highly suspicious of any Influencer who calls him or herself an “expert”. Even if the person is knowledgeable to a certain extent, the desire for clicks/followers/sponsors and thus money can often cause them to exaggerate and overdramatize in an effort to gain more attention. I think this is one of those cases. Again, most of the videos I’ve seen from this person are debunking other claims or myths that exaggerate and overdramatize food quality and safety. That’s not to say that they can’t be wrong sometimes, or even be immune to the occasional click-bait headline. But it’s not as if I’m posting this question about any random video I happened to come across; it’s from someone whose other videos I have come to respect as presenting seemingly factual evidence, displaying common sense and _not_ being sensationalistic. ---
**Author:** ![chela](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chela/32/21582_2.png) [@chela](https://boards.straightdope.com/u/chela)\ **Post date:** [July 21, 2026, 3:19pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/13 "2026-07-21T15:19:59Z")
I wondered the same thing. How serious? After some consideration I follow the package instructions, when it says remove from packaging to thaw in fridge I do. Sometimes in a hurry I’ll put the package under running water or submerged in water and 15 min later it’s usually good to go. Or I have cooked frozen fish in the oven covered for the 20 m, then remove cover and finish another 10 m or so. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [July 21, 2026, 3:30pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/14 "2026-07-21T15:30:20Z")
> [@Dewey\_Finn](#): > > I imagine that few people are going to conventionally cook the fish in the plastic vacuum package, so the only ones who might face this issue are those who plan to use the sous vide method. That’s what i think, too. Botulism doesn’t grow very quickly in the fridge, so the two normal ways of thawing it, overnight in the fridge, or for half an hour in cold water, are both pretty low risk. And the number of people who sous vide fish is small. So you wouldn’t see a lot of problems. > [@Shoeless](#): > > Usually the vacuum-packed fish has instructions for cooking it frozen or thawed. If frozen, it just has you leave it in the oven for a few more minutes. If you’re worried about thawing it, just cook it straight from the freezer. Naw, it comes out MUCH better if i fully thaw it before cooking. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [July 21, 2026, 3:34pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/15 "2026-07-21T15:34:38Z")
This must be an American problem. I buy what we call ‘boil-in-the-bag’ kippers. They are smoked fish, sealed in a bag with some butter and cooked by immersing them in boiling water for 15 minutes. Yummy! The same people sell other fish, like cod in parsley sauce, but that isn’t all that nice. I take the attitude that if I follow the instructions, I won’t go far wrong. ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [July 21, 2026, 3:45pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/16 "2026-07-21T15:45:50Z")
A quick check on Google shows that this is a common enough problem they all packaging is **legally required** to say to keep the fish frozen until use. The false health claims generally do not make it to the legitimate food regulation entities. I had wondered why the packages say this. I thought it just meant that the fish would go off really fast at refrigerator temps. I think “open before thawing or cooking” would be a better instruction. (And tell people why on the outer packaging. People dismiss warnings all the time that they don’t understand.) ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [July 21, 2026, 3:50pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/17 "2026-07-21T15:50:23Z")
> [@bob\_2](#): > > This must be an American problem. I buy what we call ‘boil-in-the-bag’ kippers. They are smoked fish, sealed in a bag with some butter and cooked by immersing them in boiling water for 15 minutes. Yummy! The same people sell other fish, like cod in parsley sauce, but that isn’t all that nice. That packaging is _designed_ to be immersed in boiling water, unlike the vacuum-sealed package earlier described. ---
**Author:** ![Eyebrows\_0f\_Doom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eyebrows_0f_doom/32/3119_2.png) [@Eyebrows\_0f\_Doom](https://boards.straightdope.com/u/Eyebrows_0f_Doom)\ **Post date:** [July 21, 2026, 4:05pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/18 "2026-07-21T16:05:44Z")
> [@BigT](#): > > all packaging is **legally required** to say to keep the fish frozen until use. Well _yeah_. Of course you want to keep it frozen until you defrost it. But that doesn’t say anything about not thawing it in the bag. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [July 21, 2026, 4:55pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/19 "2026-07-21T16:55:48Z")
> [@BigT](#): > > I thought it just meant that the fish would go off really fast at refrigerator temps. It does, fyi. ---
**Author:** ![ricepad](https://avatars.discourse-cdn.com/v4/letter/r/b38774/32.png) [@ricepad](https://boards.straightdope.com/u/ricepad)\ **Post date:** [July 21, 2026, 5:55pm UTC](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827/20 "2026-07-21T17:55:53Z")
> [@LSLGuy](#): > > ISTM that if the risk was statistically significant, there’d be a lot of deaths reported. Since there are not, the risk must be statistically insignificant. The fly in the ointment here could be that sous vide is not that common a cooking method, so the sample size could be very small. [Next page](https://boards.straightdope.com/t/how-seriously-should-i-take-this-warning-about-defrosting-vacuum-sealed-fish/1031827.md?page=2)