Want the best olive oil? You can buy the tastiest extra-virgin for half the price in budget supermarkets, according to Which?
A blind tasting by a panel of olive oil experts found bottles at Aldi and Lidl were better (and far cheaper) than those at the Big Four supermarkets.
The consumer group described Aldi's Evoo and Lidl's Primadonna oils, at 33p per 100ml, as 'exceptional value', each receiving four stars, along with Waitrose's extra virgin oil, which costs 50p per 100ml.
Other supermarket and branded extra-virgin oils disappointed. With 'less depth', Tesco, Sainsbury's and Felippo Berio and Bertolli Original received three stars, while Asda and Napolini were 'below average' with two stars.
At 57p per 100ml, Marks & Spencer's and, at 46p per 100ml, Morrison's oils were bottom, marked 'leave on the shelf'.
Which? said: "You don't have to dig deep in your wallet to get good quality. Of the 12 supermarket and branded extra virgin olive oils our experts tasted, two of our best buys are from budget supermarkets and, per 100ml, they're by far the cheapest on test - giving them both 'exceptional value'."
The consumer group added that, no matter how good an oil, it had to be stored in a cool, dark place to avoid losing its freshness.
Its panel comprised Judy Ridgway, an international olive oil buyer; Sam Rosen-Nash, savoury grocery buyer at Fortnum & Mason; James Wierzelewski, executive chef at Harrods; and Adam Byatt, head chef and owner of Trinity restaurant in Clapham, London.
Tasting the oils without knowing which brands they were, they described Lidl's Primadonna oil as "a delicate oil that's ideal for everyday use" and praised Aldi's Solesta Evoo's "enticing" fruity smell.
Among their less favoured bottles, Carapelli's oil tasted of "stale nuts", despite costing 84p per 100ml, while mid-price M&S's oil was "old" and Morrison's "fusty".
Lidl said the tasting accorded with the popularity of its oil. "Sales of our Prima Donna extra virgin olive oil have gone through the roof over the last few months. This accolade shows what shoppers have known for a long time, at Lidl you get premium quality products without the premium price," a spokesman said.
Paul Foley, group ganaging director of Aldi UK and Ireland, said the taste test showed it was "successfully offering leading quality products at prices significantly less than the recognised brands."
Marks & Spencer made no comment.
Morrisons said: "We are clearly disappointed with the Which? findings in this report as we constantly review our range with a view to improving value and quality. We are already re-testing and reviewing this product with our supplier."