Use it or lose it? What the date labels on your food mean
Do you know your best-before from your use-by dates?
Our survey found 77% of Kiwis look for best-before or use-by dates when buying food. Despite this, there’s confusion about what the dates mean.
For the first time, we’ve asked consumers about their food safety practices – how they protect themselves from getting sick from food, and what foods concern them the most. In this first article in our three-part food safety series, we look at best-before and use-by dates.
Most products with a shelf life of two years or less are required to have a best-before or use-by date. When buying food for the first time, it’s the labelling information most commonly looked for: more than three-quarters of people in our survey told us they looked for one of these dates. Less than half checked other information on labels such as the ingredients list, storage instructions and the nutrition information panel.
How often people check the date label depends on the type of food. Raw chicken and milk are the products people check the most, with canned foods and breakfast cereals the least.
Understanding date labels
Use-by dates are required for health and safety reasons to reduce the risk of people getting sick from food that’s gone bad. Foods with use-by dates can become unsafe before they noticeably spoil, so the food may still appear OK to eat after this date. Food shouldn’t be eaten and can’t be sold after its use-by date.
Best-before dates are about food quality. Food can be sold and eaten after it’s best-before date provided it’s been stored properly. However, it may have lost some nutritional value and might not taste as fresh. The food can still be safely eaten and does not need to be thrown out unless it is spoilt.
Despite the different definitions, 18% of people we surveyed think the dates mean the same thing; believing they both show when food should no longer be consumed. A further 5% aren’t sure about the difference.
Only about half (53%) of people know that food can’t be sold past its use-by date, with 31% unsure.
Using date labels
With the cost of groceries high on the list of consumer concerns, we asked people whether they buy food nearing its use-by or best-before date because it’s on special.
Two-thirds (66%) said yes for use-by dates, 72% yes for best-before dates.
More than half (54%) of people surveyed often or always throw away food past its use-by date. But some consumers (39%) eat food past this date to avoid wasting it. This puts them at increased risk of getting sick.
More than one-quarter (28%) often or always throw away food past its best-before date with the same number saying they won’t eat food past this date. This means a lot of food is being thrown out that can safely be eaten.
Research undertaken by Love Food Hate Waste, a national campaign to help New Zealanders reduce their food waste, has revealed that the average Kiwi family throws away around three shopping trolleys worth of edible food each year. That’s around $1,520 wasted per household.
Unsurprisingly, people are more likely to be cautious with particular foods. More than half the people we surveyed said they wouldn’t eat chicken, deli foods and packaged ham after their use-by or best-before date.
Attitudes to date labels
Most people trust the use-by dates and best-before dates on foods. But, when it comes to supermarkets selling foods with a short shelf-life, 28% are moderately or extremely concerned.
Our data are from a nationally representative survey of 1001 New Zealanders, aged 18 years and older, carried out online in June 2023. Figures may add to +/- 100% due to rounding.
This report is free thanks to funding from New Zealand Food Safety. Read more about food safety and date marking.
Date marking FAQs
We answer your questions about best-before and use-by dates.
What is a use-by date?
Use-by dates are required for health and safety reasons to reduce the risk of people getting sick from food that’s gone bad. You’ll find use-by dates on perishable foods like ready-to-eat salads and deli meats. These foods can make you sick without any signs you can see or smell.
If food is stored correctly and hasn’t been opened, it should be safe to eat up to (and including) its use-by date.
Food can’t be legally sold after its use-by date. You should not consume food after its use-by date.
What is a best-before date?
Best-before dates provide information about food quality. Food is safe to eat after its best-before date as long as it’s been stored properly and prepared according to the instructions. However, it may have lost some nutritional value and may not taste as fresh.
Don’t eat food marked with a best-before date if it shows signs of spoilage, such as smelling off or looking mouldy. Food can be legally sold after its best-before date if it is fit for consumption.
Why don’t some products have a best-before or use-by date?
Products with a shelf life of two years or more, such as canned foods, don’t need a best-before date.
Cans that are stored and sealed properly should last several years and are likely to be eaten well before they spoil. However, if the can shows any signs of deterioration, don’t eat the contents.
What other dates are found on food?
Baked-on date: Breads with a shelf life of less than seven days can have this date.
Packed-on date: Tells you how long the product has been sitting on the shelf. This information isn’t mandatory but is handy for knowing when freshness is important, such as for coffee beans.
Pressed-on or harvest date: May be found on cooking oils (the fresher the better).
Julian date: A traceability date that appears on a food product as a code. The company may include it in case it needs to trace products in a particular batch.
It’s sometimes found on fresh produce.
How long will food last after its best-before date?
This depends on several factors: a food’s water and protein content, freshness and quality when you bought it, how it’s been stored and the pathogens likely to grow on the food. If storage conditions are required for a product to keep until its best-before date, suppliers must include this information, such as “keep refrigerated”.
What happens to the best-before date after opening?
As soon as you open any packaging, the shelf life becomes the same as if the product was unpackaged. For example, sour cream should be consumed within seven days of opening, bacon within five days. This information is on the packaging.
Can I eat meat after its best-before date if it’s been frozen?
Meat is safe to eat after its best-before date, provided it was frozen before the date. Defrost and cook it within 24 hours.
Can I prolong the use-by date on food to avoid throwing food out?
You can only extend the use-by date on food if you freeze the food before the date. Once defrosted, it should be eaten within 24 hours.
Why does raw chicken have a best-before date instead of a use-by date?
Most raw, chilled meat products – including chicken – will have a best-before date. This is because they are cooked before eating which ensures they are safe to eat.
Is it safe to eat eggs after their best-before date?
Eggs are safe to eat after their best-before date but keep them in the fridge to keep them fresher for longer. To check if an egg is fresh do the float test: place it in a bowl of water, if it floats it’s no longer fresh enough to eat.
Is it safe to eat dairy products after their best-before date?
Dairy products, if stored properly, can be eaten after the best-before date. But if it smells or looks a bit off, don’t eat it.
Yoghurt can get watery over time which is the whey separating from the rest of the yoghurt. It’s safe to eat – just give it a stir.
If you have surplus milk, you can freeze it. Make sure you tip a little out before you freeze the bottle so the milk has room to expand.
How is a use-by or best-before date determined?
It is the manufacturer’s responsibility to determine the shelf-life of a product and whether it requires a best-before or use-by date. How this is determined will depend on the type of food. The company may conduct tests to determine the food’s physical, chemical and microbiological stability.
The best-before date may be determined by the eating experience – when the product will lose flavour and quality – rather than when it becomes unsafe to eat.
How accurate are best-before date labels?
New Zealand Food Safety Deputy-Director General Vincent Arbuckle said by law, all food operators must meet the requirements of the Food Act, which includes ensuring date labels are accurate. Businesses are checked by accredited verifiers to ensure they are complying with their legal obligations.