Yoghurt is a total breakfast champ (or p.m. snack) and a killer base for dips, smoothies, baked goods, and more. It also packs an impressive nutritional punch: ‘Yoghurt is a good source of bone-strengthening calcium and gut-healthy probiotics,’ says nutritionist Keri Gans, dietician and author of The Small Change Diet. It can also be a solid source of protein (many varieties, especially Greek yoghurts, contain double-digit grams of the stuff).
Despite its perks, though, it can be tricky to tell when this fermented favourite has gone from pleasantly tangy to straight-up sour — and unsafe to eat. So we turned to food safety specialist Benjamin Chapman, PhD, a professor at North Carolina State University to learn more.
Can you eat expired yoghurt?
Yes and no. While most yoghurts are fine to eat past the expiration date, any opened or fruit-on-the-bottom yoghurts should be discarded.
‘A lot of this comes down to quality — not safety issues,’ says Chapman. The date stamped on your yoghurt is an estimate of when it will no longer taste good, and this guess comes from the yoghurt brand. There’s not much science behind it.
So, yoghurt with a ‘best by’ end date that’s come and gone isn’t technically expired — and it is 100% okay to eat yoghurt beyond this date. ‘It’s really only going to get more acidic and ferment more over time in your refrigerator,’ Chapman says. ‘All that’s going to happen to the flavour is that it will get tangier.’
However — caveat alert! — not all yoghurts are created equal.
If your yoghurt has fruit on the bottom, it’s a totally different story. In this case, ‘I would stick with that date,’ Chapman says. ‘Yeast and moulds will grow on that fruit and create a totally different experience.’ (FYI, here’s what happens if you eat mould.)
And, if you already opened your yoghurt, it may only last a week past the date printed on it. This is especially true if you dipped an already-licked spoon back into the tub at any point since microorganisms in the air and bacteria in your mouth can make your yoghurt go bad more quickly, adds Chapman.
How long can you eat yoghurt after the expiration date?
If you get freaked out by expired food, know this: while it’s a criminal offence to sell food that’s past its ‘use by’ date, food manufacturers do not need to show a ‘best before’ or ‘use by’ date,
That doesn’t mean you want to dig into yoghurt that’s been chilling in the fridge for years, though. The Food Standards Agency (FSA) says that you can eat yoghurt after its ‘best before’ date, but you should check that it’s still fresh. While the USDA recommends throwing out yoghurt after one to two weeks in the refrigerator or one to two months in the freezer.
Not sure how long your yog has been sitting on the back of that shelf? It’s best to use your good ol’ instincts when determining whether to eat it or not. Allow us to explain…
How to tell if yoghurt has gone bad
Sight
Take a look at the yoghurt inside the tub. While a thin layer of liquid is normal (which is usually whey, or a liquid byproduct of the yoghurt-making process), a thick layer or puddle can also indicate that your yoghurt may be off, says Gans.
Use a spoon to stir the yoghurt slightly — if you notice a lot of cottage cheese-like lumps, it’s probably past its prime.
Smell
If your tub of yoghurt has truly turned foul, your nose will give it away. ‘Even the slightest rancid odour means that the yoghurt has gone bad,’ says Gans. Chapman agrees: ‘If there’s a terrible odour, something else is growing in your yoghurt that you don’t expect to be there.’
Taste
Not seeing lumps or excess liquid, and there’s no bad smell? Your last test is a quick taste. Take a tiny spoonful and check for funky or overly sour flavours, which are indicators of spoilage.
Got it. So what happens if you do eat spoiled yoghurt?
If your yoghurt is on the vintage side but comes from an unopened container, it may just upset your stomach a bit, says Chapman. However, if it’s bad enough to bother your belly, it’ll probably taste off enough that you won’t want to eat it.
That said, if you eat yoghurt that’s been opened and gone bad, it could cause a foodborne illness and leave you with diarrhoea, stomach cramps, and vomiting, Gans adds. Again, though, it will taste bad.
How to store yoghurt to keep it fresh
To safely make that yoghurt last, good refrigeration is key. Make sure your yoghurt goes into your fridge (The Food Standards Agency recommends that fridges in the UK should be set to 5 degrees or below) as soon as possible after you buy it, Gans says.
Once your yoghurt is in there, don’t open it until you need it, recommends Chapman. And, if you bought a larger container, make sure the spoon you use to scoop out your portions is clean — and that you reseal the container tightly after using it.
If you buy more yoghurt than you think you’ll eat within a few weeks, pop it in the freezer. ‘Yogurt may be frozen for one to two months without affecting the taste,’ says Gans. From there, defrost (or enjoy a delicious bowl of fro-yo) and spoon away.
The bottom line: You can typically eat yoghurt beyond its “best by” date, but be wary of any changes in smell or flavour and note that fruit-at-the-bottom yoghurts have a shorter life span.
More in Nutrition
Cut through the noise and get practical, expert advice, home workouts, easy nutrition and more direct to your inbox. Sign up to the WOMEN’S HEALTH NEWSLETTER