Why you should not store an open can in the refrigerator

Storing an open can in the refrigerator with remains of tuna, mussels, tomato or any other preserved food is not a good idea because metals can pass into the food and strange flavors appear, but the worst thing is that it increases the risk of food poisoning such as botulism.

Storing opened cans in the refrigerator with food scraps is common practice.

Soledad Lopez

Journalist specialized in health

Canned food is one of the safest foods that exist and can last for years without the food being altered. And once opened, who hasn’t kept a half-finished can of tuna, mussels or tomato in the refrigerator and with the complete peace of mind that nothing can happen out of the cold? However, it is not a good idea. Storing an open can in the refrigerator with food remains not only causes the flavor of the product to deteriorate, it can also cause food poisoning such as botulism .


Canning is a method used to preserve food for many years. Food is packaged in previously disinfected stainless steel containers or aluminum cans and undergoes a thermal sterilization process , where high temperatures are applied for a certain period of time to destroy potentially dangerous microorganisms, such as bacteria and yeast, ensuring that Food remains safe and suitable for consumption over a long period of time.

The cans are then hermetically sealed to isolate the food and prevent contamination, in addition to preserving its flavor, aroma and nutrients. But all this starts to be lost from the moment you open the can.


Food safety specialist Beatriz Robles, author of the book Eat Safely by Eating Everything ,  warned in an Instagram post what can happen when you keep an open can in the refrigerator: “the can is not going to corrupt and pose a safety risk. food, but some metals can pass into the food and strange flavors will appear .

“Also, it wouldn’t be the first time that you drop half of the pickle in the refrigerator, and it dirtyes (and can contaminate with microorganisms) other foods, right?” , she continues.

“And, of course, the open can can get ‘bugs’ that swarm around your refrigerator , so do me the favor of investing 15 seconds in transferring the contents to an airtight container, please ,” he says.

This last point that Beatriz Robles warns about is the really dangerous one because it is one thing for a food to lose flavor and another for it to become the source of food poisoning.


These are the main risks of leaving an open can in the refrigerator:

  • Dissolution of metals in food: cans are usually made of aluminum. Over time, a small amount of metal can be transferred to the food and this process increases when oxygen enters the can, something that happens from the moment you open it. That’s why tomato sauce can take on a certain metallic taste when it’s been open in the refrigerator for days. It usually occurs especially with acidic foods such as pineapple or tomato. Furthermore, upon coming into contact with oxygen, the food, especially if it is acidic, oxidizes and generates a black layer that is unpleasant to look at but not dangerous to health.
  • Food can dehydrate and absorb flavorsfrom other foods in the refrigerator. It is not a health risk but it is unpleasant to the palate.
  • If the can contains liquid such as pickle, it can spill into the refrigerator and cause cross-contaminationwith other foods, increasing the risk of growth of fungi and bacteria such as  Clostridium botulinum that generate the toxins that cause botulism .


You also have to be especially careful with cans of tuna and other fish such as mackerel, bonito or anchovies because if they are kept open in the refrigerator it can cause scombroidosis ( histamine poisoning). Histamine can accumulate in fish muscle due to secondary bacteria when the cold chain is not adequate.


The advice is, once the can is opened, to store the product that has not been consumed with its original liquid in a container, preferably glass, close it tightly and store it in the refrigerator . It should be consumed within 3 or 4 days.

In this way, changes in the flavor of the food and the typical metallic taste, oxidation of the food and, above all, possible contamination will be avoided .


by Abdullah Sam
I’m a teacher, researcher and writer. I write about study subjects to improve the learning of college and university students. I write top Quality study notes Mostly, Tech, Games, Education, And Solutions/Tips and Tricks. I am a person who helps students to acquire knowledge, competence or virtue.

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