There may be less air left in the jar, but heated air is still air. I would not call that a vacuum, but it might be sterile air. I don't know. You could ask on the Harvest forum - people there do a lot of canning.

I have a jar attachment for my Foodsaver, and I remove air from jars with that.

Katie, I'm not a canner but have read the Harvest forum quite often because I find it so interesting. I always thought a vacuum was not enough. The jars had to heated to a certain degree and for a certain amount of time before being able to pronounce their contents safe-to-eat. And my understanding is that now, with listeria, even refrigeration is not a guarantee.

I wouldn't touch that with a 10-foot pole, personally. Let whatever it is cool, put it in a freezer bag and put it in the freezer. Food poisoning is not something to take a risk on.

The seal may be a hard seal, but there's air in that jar. It's the refrigeration that keeps the meal. I've put food in regular PP "disposable" containers, which have a water tight seal just by snapping on the lid, and it's mostly air tight--put those in the fridge and had them last at least 10 days if not 2 weeks without showing signs of decay, mold or bacterial growth. It depends on what the food is. Using sterile jars sure helps. It's the refrigeration that preserves the food. The pH balance is important too. I wouldn't keep food that long on purpose, except by freezing (or canning, which I don't do), but at least they're not trying to keep it on the counter as if it had been canned properly.

OMG no that is not safe.

Depends on the food....if it's not meat based or root vegetable in a non acid enviornment....it's perfectly safe.
that's the way our grandmothers did it for years.....and why those who know say be very careful of home canned green beans and beets unless they are pickled beets.
That's the way I "can" jams and jellies....but I top with melted parrafin directly on the food.....and there is enough sugar in there to act as a preservative.
And at 2 weeks in the refrigerator? perfectly safe!!

Nope. Would not do that. Is it dangerous? Not sure, but why take any chances especially during a time when the last thing one needs is to need a hospital/emergency visit. And the cost of that visit is thousands$.

A few years ago a well known chef posted his back burner stock he kept going all week for his family. Just kept it there, turned off and on various times. No fridge time. Just boiled it again the next day. Got a bunch of 'the horrors' for that. A super cold kitchen in a very cold climate that may work fine. He did remove the article. And apologized.

Best always to cool down hot food uncovered asap with an ice bath, then fridge, then freeze.

We did share a summer home for a few years back in our 30's with a bunch of friends. One English friend did always have a funky stock-ish thing going for weeks at a time on a back burner. Off most of the day then boil. Common in some places for sure but not worth the risk.

No, no, no, not a single chance I'd eat that. Jam? OK, if it gets moldy toss it out. This person talks about "meals", though, and low sodium, so not jam or fruit products. Absolutely not happening in my house.

I am a big proponent of everyone doing what they are comfortable with and the guidelines are just that, they are guidelines and not "The Law". BUT, I also think everyone should have all the information available so that they can make an informed choice. My informed choice is that I would never consider this method, even if it "hasn't killed anyone yet", which seems to be the most prevalent argument for this type of "preserving". Plus, I have a 1940-something Ball/Kerr book and even 70 or 80 years ago they were saying to use a pressure canner when canning meat or vegetables, it's not even a new concept.

Annie

I cover leftovers, (whether on a plate/bowl with plastic wrap or in a container with a lid), label with date (freezer tape) and place in frig. It is in clean, but not sterile containers. We use up to seven days. If not ate or frozen by the 7th day, it is discarded. Stuff that freezes and reheats well, I prefer to freeze, so we have a "new" meal when I don't want to cook.

I love candied figs. Fresh figs are cooked with a small amount of water and a lot of sugar until they are candied. I put in sterile canning jars, while hot, let the lids snap down, and put in frig. They are fine for at least a year, if I don't eat them first. My grandmother just put them on the shelf, but I don't.

My grandmother, father, and mother in law, always made jams and jellies by cooking down and putting in jars with parafin on top. Those were always stored in the pantry.

My father always canned tomatoes by just peeling, putting in jars, (no salt or anything else), and doing a boiling water bath. They were always fine. I tried it in the '80's, but it didn't work, they spoiled. I read later that the tomatoes were different and not enough natural acid. I have no idea what variety tomato he used.

ETA: Annie, we always just pulled the parafin off and scraped any mold off with a little of the jelly, lol.

ETA 2: None of them canned meat or vegetables, other than tomatoes, Dad liked frozen better and my grandmother just cooked and ate what she had.

Here is my go-to for any food preserving questions:

https://nchfp.uga.edu/

Thanks for the replies. I guess the statements about creating a vacuum And nothing can grow in a vacuum bothered me. I’m no canning expert, but would pouring hot food into a jar and then immediately sealing it create the quality of vacuum that would keep cooked food fresh for two weeks? I know it’s stored in the fridge, but with Listeria, even that is not a guarantee of safety.

I fall into the “why take the chance” category. Seems to me that sealing while it’s piping hot means that it’s going to take a long time to cool off. So, more opportunity for weird things to grow in the food. I’m not sure that I’d trust the vacuum seal created by the reaction of the lid to the hot food cooling. Bottom line for me is that I think there are better ways to preserve easy-to-use meals.

Shambo, as was said before, it depends on the food. If it were strawberry jam, probably. Maybe even pickles if the the brine is at least a 50/50 ratio of vinegar to water. But "meals"? Unless it's a high acid fruit or appropriately acidified with vinegar/citrus/etc, or composed of dried ingredients that won't spoil, etc., that's just not going to be a good way to try to meal prep.

Tigereye, we also pulled off the paraffin and if the jam was moldy Grandma would scrape it off and we'd eat the rest of the jam. Well "we" meaning everyone except me, I could still taste that flavor and wouldn't eat it and I could tell, even if Grandma tried to sneak it onto my toast! She quit using paraffin when I was still pretty small because she said paraffin was messy, hard to deal with and she "lost" jam to mold, something that nearly killed her. She started using "rings and flats" and doing a boiling water bath and so that's the way I do it. I've tried paraffin and I'm just so bad at it, I'm not patient, it messes up a pan hopelessly, I've even set a pan of paraffin on fire. And that's before the jam molds because there's an air hole or a leak somewhere in the was seal. Now, some others are really good at it and it does allow people to use fancy glasses to store their jam, which makes pretty presents and as long as you're good at it it's an acceptable method, I'm just not good at it, I'm too impatient. So I slap on a lid and a ring and into boiling water, it's just faster, cleaner and easier for me.

Dad used to "open kettle" can tomatoes and dill pickles and I guess they kept on the shelf for a period of time, and tomato IS a fruit, so there's that. I never had good luck with it and today's tomatoes are lower in acid than they used to be, so I'd rather be safe than sorry. Same with pickles, I'll make refrigerator pickles and they'll keep for months in the fridge, but if they go on the shelf they get a ring and lid and the hot water treatment.

Annie

There's a difference between void of air vacuum and a vacuum seal. As Dcarch will say, even a vacuum sealer doesn't suck out all the air. A vacuum seal is about the quality of the seal. It's that suck it in to make a pressure difference thing. Makes it hard to get the lid off. Keeps things in and out. But it's not a preservation method.

Food lasts a lot longer than most people credit. The problem is guaranteeing it. People used to keep food on an open shelf. People also used to die from "tainted" food all the time. The point of a method of preservation, rather than just winning the is my food spoiled lotto, is that you know that it's okay to eat. Frozen food can be freezer burnt as all heck, a nasty texture, and taste awful, but if it was wrapped decently and not thawed and refrozen, just sitting there in the bottom of the freezer forever will every bit of moisture migrated and crystallized, you could eat it and it would be fine. Same with properly canned items. If they have been stored properly, and the jar/can is intact, it can be way past its best by date but still won't make you sick. That's preserved.

I saw something disturbing this evening and thought of this thread. On Top Chef the contestants were asked to make a "product" that the public could take away from their stations at an outdoor mall. They did the cooking in the show's kitchen set, and used bare hands, spoons and funnels to fill jars. No discussion of preservation or health issues. The closest was the next day at the mall where one contestant was asked if the goop needed to be refrigerated and the contestant said it was "shelf stable". Yeah right.

The only thing I can think of is that they could have had the jars actually canned. There are places that use commercial machinery for short runs. I know they can safely can things that a home canner can't even with a pressure canner, but still I'd think the recipes would have to be vetted in some way. And I really don't think they did that. I'm guessing they're covered by the cottage industry law, but I sure wouldn't want to be be tasked with poisoning people...

I make dozens and dozens of jars of jams and jelly every year.....and have for years and years and years sealed with parrafin and then a flat and screw on ring......and only once...just once out of hundreds of jars have I ever had any mold. And for years I didn't use the canning lids just covered the glass with a piece of foil.
AND.....this isn't food on a shelf....it's in the refrigerator. If the food is HOT when it goes into the jar....it shouldnt have any "cooties" in it. It in sealed with a vacuum insuring that no new cooties get it.....what's to grow? Salmolella Ecoli botulin lysteria all are killed by cooking. I would imagine the quality of some things may deteriorate but that's another matter.....and there is no mention of what sorts of foods are stored.

I used to go to a lot of farm auctions and occasionally there would be home canned goods sold with the canning jars etc. people went crazy for home canned meat of undetermined age and canning method....
EWWW!

I was assuming that by "meal", what was meant was mason jar meals, which are meat as prep ahead for eating during the week, kept in the fridge. They can be anything from yoghurt, cereal and fruit for breakfast, to add and egg omelette fixings, to salads and soups, to casseroles or shepherd's pie.

To the best of my knowledge, the mason jar is meant to be durable and inexpensive (or reused), and glass rather than plastic. It's not meant to be canned and shelf stable. The first week is fine. It's the second week that's iffy.