Can I sous vide Costco salmon filets in the plastic bags they come in?

January 4, 2019 6:45 PM

I buy frozen sockeye salmon filets from Costco, and they come individually packed in clear vacuum-sealed plastic. I would like to cook the salmon sous-vide. It would be extremely convenient if I could cook the salmon in the packaging it comes in, instead of opening it up and putting it in a new plastic bag before cooking. Will that kill me?

Here's a photo of the salmon in question.

I'm not really sure what type of plastic is used in the Costco packaging, (or how to find out). Is there an easy way to check whether the plastic is sous-vide-safe? Thank you!

posted by ripley_ to Food & Drink (12 answers total)

I'm assuming they package it in that plastic for a reason,not necessarily a cooking reason, and I'll assume the temp you sous vide it is not above any weird temp. I assume 140.

I would do it. I sometimes boil the shit out of my leftovers in the microwave. No biggie.

Some plastics engineer should pop in ( being metafilter and all), but I have eaten far far worse in much worse condition, and I'm still alive.

All boiled stuff in plastics. Like don't make a habit of it, but it'll probably be fine. 140 degrees in plastics is not much at all.
posted by sanka at 6:57 PM on January 4, 2019 [2 favorites]

It won’t kill you fast, that’s for sure.
posted by SaltySalticid at 7:04 PM on January 4, 2019 [4 favorites]

Maybe.
posted by Candleman at 7:10 PM on January 4, 2019 [3 favorites]

Best answer: Other than it melting at your sous vide temp (which you can test) or the packaging specifically stating not to heat the bag, your main concern is chemical leeching of BPAs or phthalates. Also glue or dye depending on the bag.

High fat foods like meat are particularly susceptible to leeching. I would suggest calling the manufacturer and asking what the bag is made of, and if it is safe to boil / sous vide. Even if they says it's fine, though, apparently the common replacement for BPA, BPS, is also likely to be harmful and manufacturers are not required to say what they are using in place of BPA, so. . .

tl;dr -- rebag it. it's a pain but it beats getting metabolic disorders or cancer down the road
posted by ananci at 7:19 PM on January 4, 2019 [15 favorites]

I've frequently cooked meats sous vide in the bags they came in -- often far thinner than those salmon bags -- and I've never had a problem. Then again, I tend not to give a damn about BPA or BPS or BFG or whatever all else is in plastic.

(That said, these days I'll usual rebag so I can add some seasoning, fat, and/or aromatics. My experience has been that proteins cooked sous vide totally plain are bland regardless of what I do after.)
posted by jacobian at 7:25 PM on January 4, 2019

Melted plastic in food doesn't kill you quickly. But many plastics are hormone disruptors and carcinogens, and plastic is made of oil so it's ultimately kinda fat-soluble.

It's not unreasonable to worry about bad shit from plastic leaching into hot fatty food. I mean- the proof that it happens is right in your tupperware drawer. You know those red-stained, bubbly old tupperwares that never bounced back after you microwaved chili in them? That's plastic being degraded by fat + heat.

I don't have any studies to link because it's visibly obvious to me that fat and plastic mix all too well, so I never bothered to research it, I just avoid it.

In 100 years' time, my guess is that people will probably be aghast at all the hot plastic we blithely ingested, just as we're currently aghast that people used to put arsenic into their face powder and asbestos into their houses and lead paint in their babies' rooms.

So yeah once in a while probably isn't a big deal- there are a million environmental toxins and lots of stuff happens to food that's outside your sightline- but personally, I wouldn't do it often.
posted by pseudostrabismus at 7:40 PM on January 4, 2019 [10 favorites]

Best answer: Thawing fish in the packaging is not advisable because of anaerobic bacteria - I wouldn’t risk it.
posted by zepheria at 10:05 PM on January 4, 2019 [6 favorites]

It’s not salmon, but Kenji Lopez-Alt suggested keeping a ham in its original packaging for a Sous Vide recipe. I just made this recipe at Christmas and it worked great.
posted by otherwordlyglow at 11:33 PM on January 4, 2019 [1 favorite]

This is no problem whatsoever. That bag is quite a bit more sturdy than the usual vacuum bag or ziplock that might be used, and in any event salmon is likely to be cooked at a fairly low temperature for a short time. The only thing you would be missing out on is the ability to put additional flavorings into the bag (e.g., spices, herbs, citrus, etc.).
posted by slkinsey at 5:39 AM on January 5, 2019

Best answer: This question was just asked over on /r/askculinary and the answer is to rebag it - especially if you are cooking sous-vide.

Heavily seconding Zepheria here. The concern is botulism, not BPAs.
posted by JoeZydeco at 6:06 AM on January 5, 2019 [3 favorites]

We just brought home a pkge of Costco Talapia and I read the bag carefully. At least one of the thawing recommendations involves leaving the fish in the original plastic, but that's for quick thawing, presumably followed by immediate cooking.

I have no experience with sous vide. If there is air inside the plastic, it could interfere with the heat transfer from water to fish and affect cooking times, if only a little.

Finally, I always rinse fish/chicken when it comes out the plastic because I assume, with any basis in fact, that the last thing to happen to the product before being put in plastic is that it was treated with something or other, either to kill bacteria or to preserve a fresh appearance. Neither of those things sounds tasty.
posted by SemiSalt at 9:09 AM on January 5, 2019

Apart from the health concerns, those Costco vacuum-bagged salmon filets typically have a thin layer of ice between the actual meat and the bag—so you might be simmering the fish inside the bag, which probably isn't the effect you want. I've never cooked sous-vide, but my guess is you'd want to fully defrost the fish and separate it from the excess moisture before rebagging it.
posted by adamrice at 4:38 PM on January 5, 2019