I used to be ridiculously good at throwing away food. I didn’t want to bin edible food, I genuinely believed it would kill someone if I served it. Yoghurt was a particular culprit. Yogurt two days past its date was definitely unsafe, right? Then I started looking into what that date meant, and realised I’d been tossing perfectly good groceries out of misunderstanding what those stickers were telling me.
Millions of others do it too. 29% of Brits will not purchase items without a use by date (YouGov). 17% say the same for best before dates (YouGov). Households throw away an average of 3.2kg of food a week. Best before and use by confusion accounts for some of that 21% that’s avoidably binned (UKHarvest). Food that didn’t need throwing away, tossed because we don’t understand those dates on packaging.
So how much food are you chucking because of badly understood dates? How much money could you save if you understood use by versus best before dates? How much safer would your food shopping habits be if you knew which items needed careful date management and which didn’t? This guide will cover:
* How best before and use by dates are calculated and why they matter differently
* Exactly which foods get each type of date and which don’t require dates at all
* How to adjust your shopping and eating habits to make the most of food without compromising safety
The science behind the system
First up, a brief rundown of how the use by and best before systems work, because they actually use real science to determine those dates on your food.
Use By Dates
Use by dates are all about harmful bacteria. They’re calculated by determining how quickly common pathogens can multiply in a given foodstuff to dangerous levels in normal storage conditions.
That means food safety scientists take a product, contaminate it with known levels of common pathogens like salmonella, listeria, or e.coli bacteria, then store it at a range of temperatures. They regularly sample the bacterial levels during storage to see how quickly they increase. The use by date is when those levels could reach a point where you become sick if you eat the food.
It’s not guesswork, or averages. The standards used to determine use by dates factor in fridge temperature fluctuations, the fact that some people don’t store products in ideal conditions, and then apply safety margins to make sure vulnerable people are protected. Eat your food on the use by date but not after, because after that date there is a real risk of food poisoning (Food Standards Scotland).
Best Before Dates
Best before dates aren’t about bacteria at all. They’re about quality instead. Best before dates are when the manufacturer can guarantee that food will taste, look, and feel exactly as it should based on how they’ve processed it.
They’re still scientific, just focused on non-bacterial chemistry. When fats go rancid, when proteins break down, moisture has time to migrate through packaging. Flavours lose their punch. Textures change. Enzymatic reactions alter fruits and veg too.
Food should be safe to eat after the best before date if it’s been stored correctly (Food Standards Scotland). The crisp packet might be bloated, forcing the biscuits to soften. That cake may lose moisture and go stale. The chocolate may have white bloom and lose flavour. But they will still be safe to eat.
The Law
Contrary to what most consumers believe (YouGov), use by and best before aren’t two ways of saying the same thing. In fact UK food regulatory bodies are very clear about the difference (Food Standards Agency).
Use by = Safety. Best before = Quality.
The regulations that decide which products get use by dates, and which get best before dates are legally binding. They cover both what products get which type of date label, and what those labels actually mean.
Foods That Get Which Date
There’s method to the madness that is use by and best before dates. Certain classes of food almost always get one or the other.
Use By Date foods
Fresh products. Things that are likely to support rapid bacterial growth as they age and deteriorate. Fresh meat, fish, unpasteurised milk, soft cheeses. Prepared foods like salads, sandwiches, and ready meals. Basically, if you’re putting it in the fridge it’s potentially got bacteria in it that could make you sick if you wait too long.
Moisture content and PH levels matter too. Highly moist, low acid foods are more vulnerable to bacterial contamination. High protein count is another trigger because protein rich foods feed bacterial colonies too.
Best Before Date foods
Pretty much anything else. Shelf stable products. Preserved foods where safety isn’t an issue before quality. Tinned foods, dried pasta and rice, flour, biscuits, chocolate, frozen products. Dairy gets tricky because some technically come under use by, some don’t despite also being dairy. Butter and hard cheeses often get best before dates.
Eggs are interesting because they get a best before of no more than 28 days after being laid (Food Standards Scotland). Fresh isn’t the same thing as use-by. The shell and natural coating protects against bacteria, but not indefinitely. The quality reducing reactions happen before the bacteria make your scrambled eggs unsafe to eat.
Products that Legally Don’t Need Dates
Fresh produce not sold on a trunk farm don’t require dates. Most bread and bakery products are also exempt if sold within 24 hours. Alcohol over 10% ABV, vinegar, salt, and sugar.
What you can safely eat after the date
We’ve covered the whys. Here’s the practical upshot and how you can start wasting less food.
Best Before Dates
Pretty much everything is fine assuming it’s stored properly and shows no signs of spoilage. I regularly eat canned foods months after their best before dates. Dried pasta and rice years after. Hard cheeses weeks. Chocolate develops white bloom but will still keep months past its date. Biscuits get a little soft but aren’t dangerous. Frozen goods keep far past best before dates but watch out for freezer burn and ice crystals which affect flavour and texture. Dried goods will last years assuming they stay dry and don’t get eaten by pests.
Look at the food. Smell it. Does it look and smell normal? If so, it’s almost certainly perfectly safe. If you see mould, smell something off, or it has an unusual texture, bin it. Don’t bin things just because it’s past the best before date.
Use By Dates
Much more carefully. Official advice is simple: throw away food after the use by date. But there’s some important information and practical tips to take on board here.
Remember temperature control is assumed in every use by date. If your product has been properly refrigerated at 5°C or below during its whole shelf life, then bacterial growth is slowed considerably versus what the standards assume. If your fridge is warm, or you leave things on the counter that need to be refrigerated, bacteria grow much faster.
Freezing stops bacterial growth dead. Just about anything you’d stick in the fridge can be frozen before its use by date and then safely eaten after defrosting (Food Standards Scotland). Freeze meat and fish before use by dates expire. Freeze leftovers. Batch cook with use by dates in mind then freeze meals.
Some items that have use by dates are better than the dates imply. Milk lasts longer than its use by in the fridge if it’s properly stored, but tastes pretty rank by the time its technically safe to drink. Hard cheese with use by dates are almost always okay for weeks past if there’s no sign of mould. Eggs can technically be eaten weeks past best before if stored correctly.
But remember these are use by dates. Designed to protect you from food poisoning. The risk isn’t zero after the date because regulators assume happy median temperatures and perfect fridge safety margins. But if you’re knowingly eating meat, dairy, or fish past its use by date you are eating at your own risk. And that risk is significant if you’re pregnant, young, elderly, or have compromised immunity.
Mistakes people make with food dates
Mistake #1: Treating dates the same. See the introduction. Having one set of rules for use by and another for best before dates spoils everybody.
Mistake #2: Storing incorrectly. Follow date rules to the letter but leave raw chicken out on the counter all day and then roast it. Food safety dates assume proper storage. Flout those and there’s no meaningful difference between use by and best before.
Mistake #3: Obsessing over degrees. Your kitchen will never be kept at a constant 5°C. Deal with it. Use by and best before dates are guidelines, safety buffers. They don’t need to be met with clinical precision.
Mistake #4: Taking ‘freezes as dated’ literally. You can freeze food before use by dates to keep it safely longer. But you can’t freeze something that’s already gone past its use by date and make it safe to eat.
Mistake #5: Skimping on fridge temps. Your fridge is supposed to run at 5°C or below. If you’re packing it so tightly no air can circulate and the temperatures climb, chill out on stockpiling. Bad temperatures mean use by dates aren’t meaningful.
Mistake #6: Confusing dates with intelligence. Literally every date on packaging is calculated by scientists. Real people. Learn to trust those who understand it better than you.
Research Sources
There’s a wealth of official resources and academic research behind the findings here. All food standards agencies perform regular checks to ensure their date calculations are correct, and that pathogens aren’t developing resistance to storage and basic preservation.
Government agencies base standards and information on what consumers actually understand (YouGov). Guidelines help inform what needs stricter date control or labelling (YouGov), and what dates are being used effectively.
Consumer research highlights why dates cause anxiety and how best to alleviate it. Advice consistently stresses use by dates are about safety (Food Standards Agency, Food Standards Agency, Food Standards Agency). Best before dates aren’t laws, just guarantees from stores and manufacturers the food will taste as expected.
Dates don’t exist in a vacuum, and careful grocery shopping with an understanding of the differences between best before and use by dates impacts other behaviours in positive ways.
Shop End of Day Discounts: You know the stuff supermarkets reduce at the end of the day? Meat, bread, cakes, deli items? Almost all of it will be fine today, even if it doesn’t have long use by dates. Freeze what you don’t use immediately.
Stock up when it’s on offer: If you know product has months shelf life before best before or freezing for later, buy when it’s cheap regardless of date.
Buy with actual consumption in mind: Freshest food is better. But if you know you’ll use a product within its use by date don’t be afraid of buying longer-dated items.
Ask for freezerscale discounts: If there are dented cans or damaged packets at the end of the day, ask your supermarket for a discount. You can often buy damaged goods for less than half price just before closing time.
Don’t worry about impulse buys: Come across something not on your shopping list that you know you’ll use today? Go for it. You know it’s safe because you understand the dates.
Learn to store food properly: Bald. Empty shelves make food waste more visible. Buy less but store correctly so what you have lasts longer.
Conclusion
Understanding use by and best before dates saves money. The average family wastes £470 per year (>https://www.sustainablefoodtrust.org/news/how-much-food-do-we-waste-at-home/). A lot of that is avoidable. You could halve your food waste and save £230 a year just by understanding use by versus best before dates.
Understanding which foods are risky helps prevent food poisoning. Millions of people get sick from foodborne illness in the UK every year. Learning which foods are perishable and need careful use-by monitoring is the first step to keeping your family safe.
You’ll eat fresher food: Counter intuitive but true. Once you stop automatically throwing things away pre-date you become more aware of food quality. You’re not chucking stuff prematurely, so you take more care with what you buy and how you store it.
This isn’t meant to be a comprehensive guide. The resources linked throughout cover each point in detail. I recommend reading through those linked articles and incorporating what works for your household into your shopping and eating habits.
The best part? Once you know how to shop smarter, and safely eat food beyond best before dates your new habits will spread to other areas of your grocery spending. You’ll become a better chooser of food based on when you’ll actually eat it, not arbitrary markers on packaging designed to reduce manufacturers’ and supermarkets’ liability.
What dates mean isn’t arcane knowledge held by shops and supermarkets to part you from your money. Food dates aren’t random, or conspiracies designed to make you throw food away. They’re carefully calculated to let you know when food becomes a potential risk to your health.
Share your tips for #WastingLess in the comments below and let’s start reducing food waste together.
