Ewww! What is that? Green mold on my favourite cheese!? Oy, I only bought it… like 3 weeks ago! I imagine that scenario is very familiar in most of your kitchens – reaching for your favourite food and BAM, it’s expired! Dear Teachers and fellow students. Have you ever taken a minute to think about how and why food expires ,what mold is and the dangers of eating expired food?


Examples of foods that expire are: meat, fish, bread, eggs and dairy products. Some of these foods come in clearly marked packages, but others are just lying loose on your counters or in your refrigerators. 

The foods in packages help tell you when something is expired because they go over the expiry date written on them. They may also look or smell terrible! 

But the unpackaged foods, like fresh fruits and vegetables, don’t have expiry dates written on their peels. So, you need to use your other senses to tell when they expire or get moldy.


What is rotten food? Some foods actually grow mold, but others just go bad/over-ripe. MOLD!! Green. White. Sometimes black and crusty… all signs of the dreaded mold!  

Mold starts off white and fluffy (like that streak on last week’s bread) then turns like a greeny turquoise colour (picture that container of cottage cheese that has been sitting open in your fridge for over a month), and soon after will turn black. It’s probably ok to cut off the white spots on old cheese, but you definitely throw it out once the more interesting colours show up. 

Mold forms when extra fermentation happens which is the result of yeast reacting with carbohydrates. So, this extra fermentation happens in foods like dairy or grain which have lots of carbs. Other foods just continue their ripening process until they are yucky, like mushy bananas, or wet spinach. 


Eating rotten foods can cause a lot of different problems. Eating expired foods can cause common things like nausea, coughs, or vomiting. However, it can also cause severe illnesses, like food poisoning, E. coli infections, or damage to the kidneys which can be a life threatening situation. Some examples of foods that are dangerous to eat when expired are: fish, pre-made salads, shrimp, fruits like raspberries, milk and other produce.

However there are ways to avoid getting sick. You can follow the three types of dates on some food products like Sell By, Best By and Use By. You can also avoid eating the foods that look or smell wrong, because our senses know when something is starting to go bad. 


We can all agree that eating expired food is disgusting. Food is important in your life but sometimes it can be very dangerous. There’s a joke that in every family, there’s someone who ignores expiry dates and eats yogurt 6 months after the best-by date,(my mom) and another person who throws everything out the moment it expires ….(my dad\) Which one are you?

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