Licensees are continuing to serve cask ale that is too warm, according to beer quality watchdog Cask Marque.
As a result the organisation is launching a new summer campaign called "Cask is Cool" to ensure licensees serve cask ale at the right temperature of between 11ºC to 13ºC.
In a survey of 2,000 licensees, inspectors from Cask Marque found a worryingly high number of licensees were still serving warm cask beer - one pint, served in a Kent pub, was even measured at a tropical 35ºC.
Paul Nunny, director of Cask Marque, said the purpose of the campaign was to get people to understand that cask beer was not best enjoyed warm.
"There is a common misconception that cask beer is intended to be warm, whereas in reality it shouldn't even be tepid, let alone warm. Proper beer is cool, refreshing and thirst quenching," he said.
He added serving warm beer could adversely affect your sales. "Getting the temperature right is critical at this time of year. Weather forecasters are predicting a scorching summer and if the serving temperature is too high drinking ale becomes memorable for the wrong reasons."
The results released by Cask Marque inspectors covered the period from July 2004 to February 2005 and showed that 44 per cent of pubs were serving cask ale above the 11ºC to 13ºC threshold.
There were licensees in London, Essex, Middlesex, Cambridgeshire and the West Midlands who pulled pints measuring between 25.9ºC and 28.1ºC - just below the temperature of a heated swimming pool.