"Best before" is mostly meaningless (in Europe). It's an exceedingly pessimistic manufacturer estimate of when the product might look, taste or feel different, not when it may become risky. Chocolate may have developed a little white bloom from the oils separating a little but still be perfectly edible and delicious etc.

Many things will keep for months or years after the best before date. One of the most ridiculous ones are eggs which will normally last months - yet have a mandated best before of 28 days.

"Use by" are the ones to take note of. Those are the perishables like milk or meat where the bacteria count matters. These are the ones that have been arrived at by food safety testing.

Even those are designed to be pessimistic enough to cope with the fact that a huge proportion of fridges are running several degrees higher than recommended, and people will leave things on the side for a few hours etc

Genuine question: are there any foods that go bad in such a way that you can't see, taste or smell it, but it can kill you anyway? (Emphasis on "go bad": things like listeria were there from the start.)

If you have a condition that means you'll react very badly to something that would most other people nothing more than an upset stomach, yes. For example, if your immune system is already compromised (from HIV, cancer, etc) something as simple as mild botulism can kill you.

About 3000 people die from food poisoning every year in the US.

Look up chubbyemu channel on YouTube. In particular his pasta episode. He is a doctor.

Why are you excluding things like listeria or campylobacter?

They were there from the start, but the USE BY date takes into account common pathogens and how they multiply in correct household storage.

> But is a small chance of dying from eating toxic bacteria worth it?

The parent is probably talking about food that's not more than a few days past expiry, since they worked in a grocery store. The risk from not following a mostly-arbitrary date is not much higher if properly stored than say, eating improperly-stored food.

A student died eating pasta stored at room temperature for five days: https://www.dailymail.co.uk/news/article-6638715/20-year-old...

Things might have turned out differently if it was stored in the fridge.

Won't pasta that's been kept out for 5 days smell very rancid?

Most likely if it's gone bad, it'll taste very bad -- nature is smart that way :)

Worst case it'll make you sick..

A regular meal can kill you too.

Things that have gone bad taste bad on their own, but if you put something bad in a meal that disguises that flavour you're unlikely to notice.

It's one of the reasons why hot countries often have spicy, highly flavored foods. Before refrigeration people could use poor quality meat for longer by covering up the taste, and it didn't kill them because lots of spices have anti-bacterial qualities.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4861184/

You can smell the ingredients before you cook spicy food..

But yeah, it can be masked.

It's a bit worrying to see people repeat the incorrect "you can smell it if it's risky" advice.

You will be able to smell if food is rotting. USE BY dates aren't just about rotting though, they take into account commonly found bacteria in different food, and correct storage.

You won't be able to smell most types of food poisoning bacteria, and the risk of poisoning goes up after the use by date.

https://www.food.gov.uk/safety-hygiene/best-before-and-use-b...

Also, the uses of preservatives, refrigeration and antibacterial agents means that the way food goes bad today is very different than the way food went bad when our noses evolved.

For example, flies circling round meat would make most people instinctively think twice before eating it. In most environments, they will appear within a few hours of the creature dying. In your fridge, the flies won't hatch, taking away a vital signal marking the age of the food.

Side note: I personally follow best-before dates. Not because I have a rational fear -- I might have some irrational fear -- but also it just makes my life simpler.

Not having decide if something has gone bad reduces decisions I have to make :)

Where is this number, "1 percent" taken from?

If you bought some milk in date that was lumpy and stank, would you drink it? Conversely if it were one day out of date but smelt and looked fine, would you throw it away?

Personally I use use by dates (I don't really check best before dates) as a shopping tool, so I buy thing that will last the time required, then rely on my senses.

Canned goods have best before dates on for heavens sake, I'd happily eat a 10 year old can of X, assuming it's none bulging.

Cooked rice is the only thing I'm aware of that can kill you after cooking, whilst still appearing ok.

In this post you confuse "use by" with "best before", even though the difference is clearly described in the linked article.

USE BY is product safety information. The risk increases after the use by date.

BEST BEFORE is product quality information. There's not much risk but the taste and nutrition will degrade over time.

I didn't confuse. Although I did change from what my parent mentioned.

Although it would be nice to have the time to check best befores and use bys of everything I put in my trolley, in practice its basically meat and milk, purely to check that they will last until I want to use them.