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Why Does It Say Do Not Reheat on Food Packaging?

Why Does It Say Do Not Reheat on Food Packaging?

How many times have you seen “do not reheat” on a food packet when you pick something out of the refrigerator for lunch or dinner? Should you really not reheat stuff that says “do not reheat”, or is it a bit like those friendly “best before” notes on the back of your ready meal?

Let’s find out.

The reason it says “do not reheat” on food packaging is because the manufacturer or producer of the food wants to ensure they are covered in case reheating the food results in illness.

Because the producer does not know what the condition of the food was in prior to reheating, they want to ensure that you know they are not responsible for any negative effects.

The Role of Bacteria

By “condition the food was in”, we mean how you treated the food prior to reheating. For example, let’s take a product that has been frozen in factory and delivered to a store. You purchase it and follow the instructions on the packet to heat it up.

You then eat most of it, but because you are too full,  you leave some for the following day. Naturally, you need to let the food cool before you reheat it.

This means the remaining food is going to cool over time, but there are two factors at play here:

  1. Where the food cools
  2. How quickly it cools

Taking no.1, the food producer has no idea whether you will leave the food out overnight, in the refrigerator, cooling on a table or even on a windowsill in the sun. This means the food may cool quickly, or very gradually.

If it happens gradually, there is much more chance for bacteria to grow – and this is the risk factor. When you go to reheat the food the next day or later that week, it may now have bacteria in it. If you don’t reheat it enough, that bacteria may not die, and could make you sick.

What’s the solution? Ensure that leftover food goes into a cool environment as soon as possible – ideally the fridge. When you do reheat it, check you are doing so at 165 degrees F (74 Celsius), and that it is heated thru when it comes out of the oven or microwave.