For all the preppers among you, you’ll know that one of the best ways to store food long term is either dried, or in a can.

Why? Well the process of canning our foods is done at a high heat, which means that dangerous microorganisms are killed, and the actual canning ensures that everything inside is kept in a sealed vacuum.

With all previous microorganisms gone, that vacuum prevents any new ones – or even just oxygen – from entering and spoiling your food.

However, cans have been a little controversial over the years, with dangerous lead once present in food cans (though this was banned in the early 90s), whilst some argue that some of the chemicals used to line cans could contaminate our food and harm our health.

Add to this the fact that salt is often used to help preserve canned foods, and you’ll realise why canned foods are generally considered less healthy than their fresh counterparts.

However, in a disaster situation, the ease of accessing and consuming pre-stored canned foods really does outweigh these health risks – so long as you’ve remembered your can opener!

But there is one other issue with canned foods: sometimes the portion sizes just aren’t what you’re looking for.

Not in a disaster situation, obviously. But if you want half a can of corn with your meal, you find yourself at a loss with what to do with the other half.

Which leads us to what most of us do – store the other half of the can in the fridge. It’s lasted this long in the can, right? Surely at refrigerated temperatures, it will last that little bit longer, even while open?

But this is where science suggests you take a step back and find another cure to your culinary headache.

That’s because, according to a 2019 research paper, the moment that vacuum seal is broken, things start to go south.

And it’s not just your food that deteriorates.

In fact, the researchers conclude that it is not unusual for ferrous and zinc metals to begin to leach into your foods, with potentially harmful effects.

Thus, the research team conclude in their analysis, the storage of open food in the can it came in should be avoided at all costs:

“Food from can packaging should not be exposed to oxygen for a long time, especially when it has been opened because it will increase the leaching of Fe and Zn metals from the packaging into food.”

Has there ever been a better time to invest in some glass storage containers?

If you found that story interesting, learn more about why people often wake up around 3 AM and keep doing it for life.