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37

Physics stops you from heating up liquids that consist of mostly water to temperatures above (roughly) 100 C. The temperature of your heating element can be set higher, but neither the temperature of the water bath nor the liquid in your jars can go higher than the boiling point where water changes from liquid to vapor - which is 100 C at normal pressure ...


26

The short answer is: No. The more elaborate answer is that certain bacteria are anaerobic and food needs to be heat treated to ensure it can be safely stored. Especial mention: Clostridium botulinum which leaves deadly toxins. The tealight inside the jar will not produce the heat needed for pasteurization.


24

The preserving effect of canning is based on removing all bacteria and fungi (normally present at least to some extent even in perfectly safe food) by a combination of heat and pressure over a certain time preventing new bacteria or fungi from reaching the food by sealing the containers avoiding oxidation by sealing the cans sometimes supporting this by ...


21

These are two different ways to preserve food. The canned salmon was boiled and then sealed into a can while it was still boiling sealed into a can and boiled under a specified combination of time and temperature that has been empirically proven to kill enough bacteria. All the bacteria in the can are dead, and no more can get in, so it's sterile and won't ...


20

These various boilings serve different purposes. The jam mixture is boiled to reduce the liquid and bring the pectin to its gelling temperature. The bottles and lids are boiled to sterilize them as you said. The final water bath kills any bugs that were introduced while filling the jars. Additionally this boiling ensures a good seal on the bottles. In the ...


20

Canned foods are by their very nature cooked once they're in the can. That's how they keep so well. It is possible to grill canned meat if you dry it first, and it may benefit from a little browning for best flavour (assuming this wasn't done before canning).


19

Assuming the can was canned properly and has not been damaged, the contents are effectively sterile, because the food is boiled in the can after it's sealed. There might be some degradation in texture and taste, but in terms of food safety, they are effectively safe. Note that the date on your tin is given as Best Before, not Use By. That generally means it'...


16

No, you should not need to boil your canned food. Most canned foods have already been heated to boiling — or higher — temperatures to kill all microbes as part of the canning process. Seafood is heated to temperatures even higher than boiling and canned under pressure. Canned food is, by definition, sterilized and hermetically sealed so unless you believe ...


16

Summary: It's impossible to give a good statistical answer to this question, since historically botulism was associated with only certain foods, and diagnosis was mostly based on symptoms occurring after consumption of those foods. Thus, old statistics include a small subset of actual cases. Actual medical testing for botulism in an ambiguous case was not ...


15

Short answer: Yes, throw it away. Long answer: Bubbling, fizzing, pressure etc. indicates some kind of microbiological activity that is unwanted for properly canned food - canning should eliminate these organisms. Any behaviour like the one you described indicates that something went wrong, so you can not assume the contents of the jar or can to be safe.


15

You should sterilize your jars and lids before every use. The dust that gets on them between uses and even in the box is enough to warrant sterilizing. It doesn't take long. Running them through a cycle in the dishwasher with a steam or sterilization step is enough. I boil the lids in a small sauce pan. Edit Debbie M's comment below made me think that ...


14

No, it isn't safe, water bath canning is only safe for high-acid foods as the acid kills botulism. Low-acid food must be processed at 240F, 116C, and that can only be achieved in a pressure canner. When you pressure cook the soup it kills the bacteria, however when you then transfer it to the sterilized jars it could be contaminated on the way, and then ...


14

That passage is suggesting an entire canning/processing method, one that may not be safe. It will generally work to create a seal, as they say, but it may not fully sterilize the contents and the seal will not be as likely to hold. I would not follow their instructions, and instead process your chutney according to a trusted canning recipe you find elsewhere....


13

Canned salmon is sterilized. Sterilization uses heat to render a product safe. Cured hams are preserved with salt, and nitrites in some cases. Some hams are also cooked. Furthermore, some fish is salted and dried for curing purposes. Salt and drying greatly reduce water activity to render a product safe. Two different processes, both create a safe product.


12

Obviously, every manufacturer is going to have their own proprietary methods. However, canned goods are often made by combining ingredients (possibly partially cooked) directly into the cans, and then pressure cooking them in the can as part of the canning process. So, for example, the broth, some celery, and some carrots might be added to the open can in ...


12

The important part of the system are the lids. The ideal lids are the Mason-type (no matter which company produced them), with a flat top and a separate side piece with thread. Another type that works is the older Weck style jar, which consists of a glass jar with glass lid, plus rubber steal and metal clamps, no threads. This system is as safe as the ...


11

Those are the flavorings. Just like dill pickles have dill in them, those are what give the flavor profile that people expect from bread & butter pickles.


11

This is totally not a problem. This style of lemon preservation relies on fermentation. The salt is not intended to halt all fermentation- it just restricts it to the tasty kind. Fermented pickles are a common and traditional way to preserve food because the salt and acid and thriving tasty bacteria make a very inhospitable environment for bad bugs. The ...


10

If you put hot (or even warm) sauce in a jar, seal it, and place the jar into the fridge, as it cools, it (as well as the air in the jar) will contract. The larger the temperature change, the greater the vacuum that will be created. Most likely, what you are seeing is warm sauce cooling and creating enough vacuum to suck in that button on the lid. If that'...


9

Commercially canned food (at least in reasonably wealthy countries, which I think would include at least all of the EU) is safe to eat straight out of the can. Provided the can is undamaged, of course. Damaged, bulging, etc. cans should be discarded. You didn't say what country in specific you're in, but your country's health, food safety, etc. department ...


9

It is normal for store bought canned beans to have a cloudy liquid. This applies to previously dried, starchy beans such as cannellini, kidney, etc. The water will get cloudy also when you cook dried beans. For others like green string beans or wax beans you would expect to see a clear liquid.


9

If it's spoiling frequently, you're using an unsafe process. (Maybe boiling water bath, no pressure?) That means you should not eat anything else you've canned with the same process, because it could've become dangerously contaminated without obvious signs. The only safe way to can low acid foods is with pressure canning. You should precisely follow a ...


9

Yes. The cooking sterilizes the sauce, but adding uncooked basil afterwards has contaminated the sauce again with germs.


9

The current recommendation of the company that owns both the Ball & Kerr brands are that it is only necessary to clean the lids, bands, and jars well with soap and water before canning with them (a normal dishwasher cycle is fine). The canning process itself will sterilize them. It is also no longer necessary to heat the lids to soften the plastisol ...


8

I've never seen canned pesto, nor do I know if there is a way to do it safely. I will propose an alternate solution. Have you thought about freezing it? I've had pesto given to me as a gift before, but it was made as normal then frozen in a canning jar. It worked great. Did some more digging and eventually came across this, from the National Center for Home ...


8

Tomatoes aren't high acid, so they need the addition of vinegar or lemon juice in order to safely can with a hot water bath. Honestly, I'm not sure why you would want to make tomato sauce from canned tomatoes because for me, the whole point of canning tomatoes is because the tomatoes will otherwise go bad. But anyhow... I recommend finding a tomato sauce ...


8

Yes, you should fully process your salsa, even if you got the "hot jelly" seal just from hot packing. The reason for this is that part of the processing is to ensure that the entire contents of the jar, all the way through, is at a high enough temperature for a long enough time to be safe as a shelf-stable product. This may or may not already be true from ...


8

Yes, though to be clear, you unseal, empty the jars into a pot, heat & add sugar, (while re-cleaning/sterilizing the jars) then fill the hot jars and process. You don't just add sugar to the jars. To suit the food safety fanatics, use new lids. I, personally, figure that if I use old lids and they seal, it's fine, because it sealed, and I know that ...


8

I can't come up with a way to do this that is not problematic. First, no canning authority I can find provides instructions on how to re-can under pressure food that is already canned. The closest instructions I can find are from the national center for food preservation, which basically say "don't do it". Second, you're talking about a month between ...


8

As already mentioned - no, don't keep dairy for extended periods. Have you considered making just the sauce base without the dairy - or even without the final elements that would differentiate it from being 'generic curry' to being a masala sauce? Sauce bases can be stored for months in the freezer. I usually have containers with just enough to make a ...


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