The launch follows a successful trial in 141 Mitchells and Butlers (M&B) pubs across Britain earlier this year and will be focused on pubs in the Central England region and in select managed outlets nationwide.
The on-trade exclusive M&B trial showed that pubs not only saw a rise in their Guinness sales, but also in their overall beer sales, which grew by an average of 4.3%.
Close to 60% of consumers who tasted Guinness Red during the trial said they would definitely buy Guinness Red again.
Simon Garnett, senior innovation manager for Guinness Red, said: "Guinness Red is targeted at occasional Guinness drinkers, people who love the Guinness brand but perhaps only enjoy a pint a few times a year on occasions such as St. Patrick's Day and at the rugby. The lighter roasted barley used in Guinness Red unlocks different flavours that exist within Guinness Draught, to create a pint that contains a subtle sweetness without compromising all the hallmarks of the brand such as the smooth body and creamy head.
"The results of the trial shows there is definitely an appetite for Guinness Red amongst consumers; test outlets sold at least one keg of Guinness Red each week throughout the trial period with minimal cannibalisation of Guinness Draught sales."
Diageo's Guinness Red launch follows a number of recent brand extensions for the beer brand, including the limited edition Guiness Bread and Marmite.