A drop of the red stuff

Guinness, the dark Irish drink known as the "black stuff", could soon be turning red.

Manufacturer Diageo plans to produce a version at its Irish brewery using lightly roasted barley, which will have a reddish colour, and give it a trial run across the Irish Sea in Britain.

"If you held up a pint of Guinness to the light, the red would come through. It's a very deep red," a Diageo spokeswoman said.

Diageo plans to test Guinness Red on drinkers in British pubs in the coming months but has no plans to launch it more widely, either at home in Ireland or in about 150 other countries where Guinness is sold.

The beer, which like the traditional, darker Guinness will have a creamy white head and be poured in the two steps needed to let it settle, will have a strength of about 4.1 percent.

Diageo already sells several versions of the brew -- including Guinness Original, Guinness Draught and Guinness Foreign Extra Stout -- to cater to different tastes around the world and has tested other limited-edition varieties in Ireland in the past year.