Sous vide: can you reuse the bags if you wash them?

Factual Questions
1

(I’ve posted this on another board but it doesn’t have nearly the membership the SDMB has.)

I’m exploring sous vide cooking and I’m very intrigued. However, I cringe at the thought of throwing away one or two plastic bags after every meal. Is it safe to reuse the bags if I wash them between uses? Preferably what I’d like to do is turn them inside out and run them through the dishwasher. Would it increase safety if I let them completely air dry for a few days? Are there opinions on what bags would be best for this?

The bags don’t have to last forever but I I could get 5 uses out of each bag it would reduce my sous vide trash by 80%. Thanks for any help!

2

Many sous vide devices come with bags (or have bags available) that are expressly intended for reuse; some Frisper owners have reported as many as 18 uses. Be careful of hygiene, however, because bacterial contamination, including botulism, can be a problem.

3

I would really be afraid to do that. Bacteria is the part of the sous vide process that scares me. I suppose they would have to be bags that could stand up to temperature, so perhaps if you boiled them in the microwave?

4

AFAIK, sous vide bags are very similar to Food Saver bags. Those can generaly be turned inside-out, washed in the dishwasher (top rack, naturally) and re-used.

Regarding bacteria, Food Saver does not recommend washing and re-using bags that held raw meat. Since one of the main points to sous vide cooking is that it’s done at low temperatures, there will be some amount of risk involved in re-using bags. Soaking the washed bags in a standard sanitizer* should go a great way towards eliminating this risk.

Bags that had been used for holding cooked food or things like nuts or dry beans are OK. If the bag had anything greasy, they advise that grease may be difficult to remove completely and a good seal is not guaranteed with such bags.

  • Chlorine bleach at a rate of 1 tablespoon to 1 gallon cool water is the official word from Clorox. Soak for 2 minutes, then air-dry. Do not rinse.
5

Y’know, that’s a good question. I don’t particularly like throwing away the bags either.

I do re-use bags from the freezer - like, open 'em up, take out a couple chops/brats/whatever and re-seal. I’ve never tried it with the sous-vide bags, though.

One issue is that, at least for my vacuum-packer, to ensure a really good seal, I need a fair bit of extra bag. Whereas a small crinkle in the seal is OK for freezing, it could potentially ruin your sous-vide by allowing water in, so I end up with at least a couple inches of extra plastic. I also double-seal anything meant for the sous-vider. Once the bags are cut open, they’re that much smaller. So even if they could be re-used, I’d worry that after one or two uses they’d be way too small. But that’s my vacuum packer - it’s at least ten years old - maybe newer ones are more efficient?

As far as boiling them, I’m guessing they’d stand up to that. Sous-vide in itself is much lower temperature than a boil, though.

Bacteria-wise, I don’t worry too much. I did at first - especially since the very night I did my first sous-vide, I ended up with the most violent stomach flu I’ve had since I was a kid. I though that I’d poisoned myself with the sous-vider for sure, but I found out shortly afterwards that it was a flu going around town, probably caught from my brother who’d had it a week before I did. <whew>

Anyway, the sickness prompted me to really question just how it is that you can cook a piece of meat at 150 degrees for 12 hours and not end up with a bag o’ bacteria, and the answer is that long exposure to semi-high temperatures does indeed kill harmful bacteria. There’s an FDA publication here that gives time and temperature charts for various foods. The standard advice about “cook all poultry to 180 degrees” (or whatever) is talking about instant killing. Longer exposure at lower temperatures does the same trick.

I’d worry about grease as well. I’ve found that any bit of food or liquid on the inside of the bag can cause a bad seal. And the last thing I want is to open up the sous-vider and find that the food I’ve been cooking for twelve hours is all waterlogged.

Good timing on this thread. I’ve got 28-hour ribs in the sous-vider destined for dinner tonight.

6

This is what I don’t understand–if I wash the bag in a dishwasher why does it matter if it contained raw meat? I can put raw meat on a plate, put the plate through the dishwasher, and then use it for something else. Why is the plastic bag different?

According to this site one can pasteurize food by cooking it at 140F for a few hours. Wouldn’t this take care of any pathogens that might be left in the bag?

Part of me feels like it’s typical over-reaction in our society coupled with the fear of lawsuits. Also, the bag manufacturers would rather I throw them out every time so that I buy more bags. On the other hand food poisoning is nothing to take lightly and I want to be smart about it.