While some people will throw out anything that has the slightest sight of abnormality on it, there's always the ones that will cut off that mouldy corner of bread and proceed to make a ham and cheese sandwich.
And those people probably have reasons for doing so; mostly not to waste any food.
But, it turns out that if there's mould on your bread, you should just throw it out straight away.
A new study carried out in the US found that "with soft food, it's very easy for the roots [of the mould], or the tentacles, or whatever creepy word you want to use, to penetrate [deeper into the food]."
So, basically mould goes much further into the bread than we can actually see.
Marianne Gravely, a senior technical information specialist for the United States Department of Agriculture told NPR that while you may think you have some wiggle room with mould, it's best to just throw it out.
"I have seen mould spread from one slice to the next. I'm sure some people would really want to press the situation, but bread is cheap. Go buy some more."
Bread isn't the only food that prompts this problem, though. Soft fruit, jam and deli meat should also be thrown away if there's any sign of moulding.
However, harder foods such as chorizo, carrots, and hard cheeses can be salvaged by cutting off the mould since its roots aren't able to cut through their surfaces.
But to be on the safe side, Marianne recommends cutting off an additional inch of food around the mould.