It is estimated that good food ending up in the bin costs more than £10m. a year.
The average family could be wasting as much as £800 annually.
Guernsey Waste has teamed up with Guernsey Dairy to promote the Love Food Hate Waste message in a new way.
In the UK, milk is one of the five most wasted items of food or drink, along with potatoes, bread, home-made meals and fresh vegetables.
‘Given the quality of Guernsey milk, islanders are probably quite careful not to waste a drop. So that is not really the target for this campaign,’ said waste prevention and recycling officer Ben Henry.
‘However, by being on the cartons, hopefully every time we open the fridge we get that gentle reminder of how much we can save just by taking a few simple steps.
‘A lot of the food that ends up in the bin is stuff that has been lurking in the fridge too long, and wasn’t eaten in time, so it is the ideal place for us to be.
‘And one of our top tips for reducing waste is to check your fridge and cupboards before you go shopping to see what you already have.
‘That way you only buy what you need and can make sure you eat what you buy.’