People are being advised to not rely on the so-called 'sniff test' to detect gone-off milk.
British supermarket chain Morrisons has announced that it's removing the 'use-by' date from most of its own-brand milk products.
The cartons and bottles will still contain a 'best before' date but consumers will be encouraged to "sniff" the milk to decide whether it should be used.
The Guardian reports its part of the retailer's efforts to cut down on the amount of food waste.
However, Dr Orla Cahill - lecturer in Microbiology and Allergen Management at TU Dublin - told Lunchtime Live she doesn't believe Morrisons' approach is a good idea at all.
She said: “Traditionally the best before dates are about quality, while use by is about safety.
“Pasteurisation does not remove 100% of bacteria… you may have spore-forming bacteria… that will survive the pasteurisation temperatures.
“I don’t think it’s really advisable to remove use-by dates from highly perishable foodstuffs.”
Dangers of the 'sniff test'
Sometimes, it's very easy to tell that milk has gone off - either via smell or curdling.
However, there are also pathogenic bacteria that can’t be seen or smelt.
Dr Cahill said: “There is pretty much a neutral smell to milk anyway unless it really does sour.
“If it’s gone out of date within a day or two days and it has been kept in proper temperatures in the fridge… you’re not going to smell that going off, per se.
"It’s not really ideal to rely on the sniff test, to be honest.”
She noted that milk stored in ideal conditions could “very well” be consumable a day or two after its use-by date.
However, it still could be “risky” to consume it - especially for babies or immunocompromised people.
Shannon Porter, owner of The Milk Bar shop in Donegal - a shop that offers pasteurised milk direct from a family farm - told Andrea she's legally required to have a use-by date on her milk.
She said removing it would also increase the risk of a customer getting food poisoning - a "big risk" for any business to take.
She observed: “For my products… I have it on the back that you have to use it within four days of purchase.
“[Lab tests show] it lasts for a week. But then you have to be very careful - things like the condition of the fridge or whether it was sitting in the car all day… things like that affect your use-by date.”
