Detecting That Canned Food is Bad – 5 Easy Techniques

Canning is an essential part of sustainable home growing. It can allow you to have access to fresh and wholesome food from your garden year-round. But when it comes to home canning, safety is of paramount importance. You need to be sure you know how to tell if canned food is bad.

Several tell-tail signs will let you know if canned food is bad:

  • The can is not sealed properly.
  • The lid or can is damaged or corroded.
  • The lid bulges upwards and clicks up and down.
  • Food fizzes, bubbles, explodes, or is ejected suddenly from the can when it is opened.
  • Food does not look or smell as it should.

We should all be doing everything we can to combat and reduce food waste. But your health and the health of others you are feeding always has to come first.

Signs That Canned Food Might Be Bad

The Can Is Not Sealed Properly

If cans have not sealed properly during the canning process, these should be reprocessed, or, better yet, placed in your refrigerator and used up right away. An airtight seal is essential if food is to be stored long term, so any cans that have not been appropriately sealed will likely go bad and should be discarded.

You should certainly discard any cans that leak or breach during storage. Eating food from cans that are not appropriately sealed always carries risks.

The Lid or Can Is Damaged or Corroded

Canning jars can be reused, but the lids should be replaced. If you come across canned food in longer-term storage with a lid showing signs of rust or corrosion, it is best to discard it. Food in metal cans that are dented, dinted, or rusted should also be thrown away. It is not always possible to discern whether food is contaminated by smell or sight. So it is essential to err on the side of caution when it comes to these things.

The Lid Bulges Upwards and Clicks Up and Down

If the lid on a canning jar or metal can is bulging upwards and clicks up and down, this is a sign that there has been a breach. Again, it is important to remember that an airtight seal is essential to prevent harmful bacteria from getting in and stop canned food from going bad. So if you find a metal can with a bulging or clicking lid, do not open it. Discard it right away. If you have a canning jar with a bulging or clicking lid, open it carefully, dispose of the contents, and very carefully clean and sterilize the jar before reuse.

Food Fizzes, Bubbles, Explodes or Is Ejected Suddenly When a Can Is Opened

Canned food that is bad will often show signs of fermentation, with gas bubbles forming. Violent ejection from the can when it is opened is an obvious sign that something has gone wrong. If there is a violent reaction of some kind when canned food is opened, this is not a good sign. Carefully clean up any mess, and discard any food that has come into contact with the spilled material.

If a can is spoiled, it is crucial to handle it carefully. Do not touch or eat any of the food. And practice good hygiene to avoid contamination. Botulism and other pathogens can be too high risk, and it is not worth taking any chances.

Food Does Not Look or Smell as It Should

It is important not to rely on the look or smell of the food alone when trying to work out if canned food is bad. It will not always be immediately apparent that the food has become contaminated. But while you cannot rely on these things alone, the look and smell of canned food is certainly something to which you should pay attention.

If you are in any doubt, err on the side of caution. Small changes to the color, texture, or smell of the food you have canned can all be clues that something has gone wrong.

Never taste any canned food that you have any doubts over. Dispose of the food carefully to avoid the risks of contamination. Your eyes and nose cannot be relied upon entirely, but sight and smell can give you some clues to watch out for.

How to Prevent Canned Food From Going Bad

Canning Home Grown Food Safely

It would help if you were sure to follow all the instructions when canning in the first place. Canning is easy once you know what you are doing. And it is something that anyone can do. But it is vital to follow canning instructions from a reputable source.

It is also a good idea to choose trusted, name-brand canning jars with an excellent double lid section system. Investing in some proper canning jars and using them correctly is vital to ensure that food does not go bad, and everything goes according to plan. Skimping at the early stages can increase the chances that something will go wrong.

You must also make sure that you follow canning instructions suitable for your location (altitude plays a role in the times required for water bath canning, and details for pressure canning too).

Remember, different foods will require different procedures to can them safely. Certain foods can safely be canned through water bath canning, while other low-acid vegetables, meats, etc. must be pressure canned for safety.

Open-kettle canning is not as safe as the methods mentioned above and increases the chances of health problems due to the consumption of improperly canned produce.

Canned food is far more likely to go bad if the foods have not been canned correctly. There is a lot to learn about home canning. And, unfortunately, there is a lot of misinformation out there.

One important way to know that home-canned food is good is to increase your confidence in your canning ability and to learn more about safe canning procedures. The more you learn about home canning, the greater the chances that your food will stay safe and healthy to eat throughout the year.

Other Methods to Reduce the Chances of Canned Food Going Bad

Once you have canned and processed foods correctly, it is essential to store them correctly too. And to be organized in the way that you manage and use your food stores.

It would help if you always practiced stock rotation in your home-grown pantry. Make sure you know when all your preserves were canned and have a sound labeling system in place. Use up older canned food before you move onto more recently canned items. The organization is the key to food safety.

While properly canned food can often last for years, I believe it is best practice to can enough for a year’s supply – eating most of the food you can in summer and fall over the next twelve months or so. Making a plan for year-round growing and eating and being organized can make a big difference in how safe and sustainable your efforts will be.

It is also crucial to keep your canned goods in an appropriate cold store, pantry, or root cellar space. Canned goods must be stored in a location without extreme temperature fluctuations. Space should be cool and relatively dry, ideally with temperatures between 50 and 70 F (10 and 21 degrees C) and certainly below 85 (29) degrees.

It is never a good idea to take a chance on any canned foods that you know to have been stored improperly or exposed to less than ideal conditions. If using canning jars, store them with the rings off, so you don’t have any explosions and so you can tell more easily if something has gone wrong. Do not double stack cans if you can avoid it.

There is no point in taking any chances when it comes to food safety. While many properly canned and stored foods can be very safe and nutritious to eat, getting it wrong can be dangerous or even deadly. Don’t take any unnecessary risks when it comes to canned food.

Check over your canned food regularly, so you spot any problems right away. And follow all the best procedures to make sure you and your family are safe. Canning food is a wonderful way to live more sustainably and take back control over what you eat. But always keep food safety in mind. When you do, and when you use basic common sense, there is far less chance that anything will go badly wrong with your canned food.

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