It might not look like it’s gone off but there may be all sorts of nasties lurking in that two-day-old hummus in your fridge. We all hate wasting food but, faster than bananas can go brown or bread can turn mouldy, there will be a pot of dip in our fridge that is out of date before we get the chance to finish it. As we peek beneath the thin sheet of plastic – now that proper lids have been ditched at some shops – and see no mould despite an old use-by date and warning to “consume within two days” of opening, it’s tempting to get out the crudites.

But doing so could be risking our health, warns Dr Primrose Freestone, a microbiologist at the UK’s University of Leicester. How quickly do dips go off? Two days is all it takes for dips to become unsafe to eat, though this can happen faster, she warns..