Sharp's Brewery has announced record sales figures for 2010 after shifting around 24 million pints of Doom Bar.
The Cornish brewer says it has doubled the volumes of the beer sold from 2009, with just five per cent of the brand's sales coming from the off-trade.
Doom Bar is the second best-selling cask brand across the Enterprise Inns estate.
Joe Keohane, director at Sharp's said: "We are delighted with the progress we are making with Doom Bar and we are particularly pleased that its success is helping hard-pressed licensees give people a reason to visit the pub.
"We believe that Doom Bar has the potential to not just be the biggest cask beer brand in the on-trade but the biggest ale brand in the on-trade within three years.
"The growth is cask beer is set to continue and Doom Bar is a brand leading that movement and we feel it can become bigger than the major keg ale brands."
Ted Tuppen, chief executive of Enterprise, said: "Sharp's proactive approach to marketing their brands, with high levels of pub specific support and working in concert with our head office team has helped take Doom Bar, within five years, from local Cornish ale to our second biggest brand nationally with strong sales across the South and particularly within London."
According to CGA Data Monitor, Doom Bar is the number one selling cask brand in the South West and Wales, and the fastest growing cask brand in Greater London.