Rekindled by Hugh Fearnley-Whittingstall’s War on Waste programme, contributions to the seemingly intractable food-waste debate are piling up like an overstuffed compost bin. Environment secretary Liz Truss admitted that she ignores best-before dates; hardly a shocker that, because most people who have a grasp of the keeping properties of food do the same. Such is our creeping disillusionment with supermarkets, many of us are now inclined to trust our intuition as to whether a food can safely be used in some way or other. Such scepticism is a wholly positive trend – the best-before date has always been deeply dubious.

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Its ancestor was the sell-by date, introduced by M&S in the 1970s, designed as a stock-control aid that would enable retailers to ensure a respectable turnover of products. Now that more processed foods were filling up our shelves, keeping a track of the life story of their multiple ingredients was complicated. The 1980s ushered in BSE and heightened concern about food provenance. Unobtrusively, sell-by dates conveniently assumed the role of a food safety marker.

By the 1990s it was patently obvious that in households where nobody had a clue as to how long certain food might last in the natural course of events, sell-by dates were generating record waste. Made paranoid by the date stamp on the packet, we didn’t think to pare the mould off otherwise sound cheddar, or bake with old eggs. The store manager’s stock-management tool had turned into the consumer’s food rotation treadmill. We meekly binned the uneaten salad leaves left over from last week’s supermarket shopping to make space for a new “fresh” bag of salad leaves from the most recent shopping trip.

As this needless waste became a focus for campaigners, the sell-by date gave way to the two alternative labelling aids we have now. Use-by is the sterner of the two, code for “ignore this date at your peril”. Best before is more forgiving, essentially the manufacturer’s estimate of the period within which you can eat the food in its optimum condition. The criteria for applying these two terms is not set down in law, or overseen by external experts, but decided in the food factory.

Even ignoring the fact that manufacturers and retailers might have a vested interest in getting us to buy more of their products than we may strictly need, this binary system is as full of holes as Swiss cheese. Given that 73% of chicken on UK supermarket shelves is already contaminated with the notorious pathogen campylobacter, can such poultry really be considered fit and safe to eat even within its use-by date? Someone brought to my attention a tin of harissa paste with a best-before date of 2099. “I seriously doubt that any bacteria known to man would even dream of attacking it,” he quipped. I am also vaguely amused by the walnut cake from Tesco that I have on my desk - it still has no mould on it, despite the fact that its best-before date was for 16 March now passed - but somehow I haven’t got the stomach to eat it.

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Both use-by and best-before dates have been endowed with an authority and a legitimacy that they do not deserve, and allow food manufacturers and supermarkets to play around with the concepts of freshness and safety. They employ techno-fixes, such as Modified Atmosphere Packaging to extend the shelf-life of their products to endow them with a “fresh-like” quality. They can use year-old frozen poultry from Thailand and Brazil, and thawed chopped frozen onions, then have the nerve to label such chilled products with a date that implies they will still be “fresh” up to 10 days after manufacture. But who would come across their own 10-day-old food in the fridge and still feel positive about eating it?

A good old-fashioned “domestic science” teacher could give us all a quick crash course in what foods to use until when. Anything that is very salty, sugary, fermented, or vinegary will generally keep for ages without the need for chemical preservatives. Fresh foods that have gone off generally stink. Extreme heat kills off dodgy bacteria. But the provenance of the food source is all-important; integrity isn’t a quality you can date stamp.

But perhaps the more important lesson to learn is that we will always be on the losing side in the war against waste as long as we allow supermarkets to lord it over our food chain. Waste, whether by best-before date, by the imposition of ludicrous cosmetic specifications, or unnecessary packaging, is hardwired into the supermarket system. Until we stop deferring to supermarkets’ own advice on what we may eat and when, those bins will keep filling up.