text: South African firm Famous Brands signed a £120m deal to buy the chain from Nando's owner, Capricorn Ventures.
  Gourmet Burger Kitchen, founded in 2001, was a "pioneer of the premium burger revolution", Famous Brands said.
  The company says that it wants to open 10 to 15 more burger restaurants a year in the UK.
  The mass-market burger giants, McDonalds and Burger King, first opened in the UK in the 1970s. While those brands have continued to expand, by the end of the 1990s a new fashion for more expensive burgers had arrived, again from the US.
  Upmarket burger brands in the UK now include Byron, Shake Shack and Five Guys, as well as an increasing number of independents. According to analysts Mintel, the premium burger market now accounts for sales worth more than £3bn a year.
  Famous Brands plans to double Gourmet Burger Kitchen's 75 UK stores in the next five years and said Brexit uncertainty would not affect its plans.
  Consumers still want food that is quick and convenient, but are willing to pay for better ingredients, said Famous Brands' Kevin Hedderwick.
  "The fast-casual premium environment is pretty recession-proof," he said.
  The price difference between upmarket and fast-food burger shops is quite striking.
  Whereas a typical McDonald's quarter-pounder with cheese will set you back less than £3, a Gourmet Burger Kitchen 4oz classic cheeseburger is more than £6. But Gourmet Burger Kitchen also sells more unusual fare, including buffalo burgers and Persian lamb.
  Food fashions in the UK range from the super-health-conscious to the indulgent. And at the indulgent end of the scale, consumers are focusing on the quality of the ingredients and being able to personalise the menu, by selecting different options.
  "Consumers see freshly made burgers as the biggest marker of a gourmet burger venue, something that sets them apart, as this is not traditionally offered by fast food venues," said Kiti Soininen, head of UK food and drink research at Mintel.
  "Customisation is also a top expectation for gourmet offerings, in line with a more general demand for knowing what goes into one's food and the trend for personalisation."
target: Wimpy owner Famous Brands has swallowed UK chain Gourmet Burger Kitchen, as the fashion for upmarket burgers in the UK shows no signs of slowing down.