Whisky and beer enjoy common ancestry. They are both grain-based drinks, with the finest interpretations made with malting barley.

In the mists of history, Highlanders in Scotland and people in faraway China boiled beer made from grain but without hops, allowed it to ferment and then distilled the liquor that was created. In Scotland they called it “uisge beatha” or the water of life, a name that became whisky.

The marriage of beer and whisky has been brought to drinkers’ attention as a result of the pioneering work of Innis & Gunn in Scotland. Today many brewers world-wide age beer in whisky casks but the method was created as a result of a fortuitous event in Scotland early this century.

Dougal Sharp is the former head brewer at the Caledonian Brewery in Edinburgh while his father Russell ran the brewery following many years working for the whisky maker Chivas Regal, where he made a close study of wood ageing.

They were approached in 2002 by the distiller William Grant and asked to supply beer for its Cask Reserve range of whiskies. The plan was to fill casks with beer and soak the wood but it would then be thrown away before the casks were filled with whisky that would pick up the flavours of the beer.

But instead of being thrown away, the beer was drunk by workers at the distillery, who said they found it delicious. Douglas and his brother Neil tasted the beer and they were sufficiently impressed to launch their own company, Innis & Gunn, to make oak-aged beer. The name of the company comes from the brothers’ middle names and they were backed in their venture by their father’s good will and experience.

Oak Aged Beer, 6.6 per cent, became a sensation when it was launched in 2003. It’s brewed with pale, amber and crystal malts and hopped with Styrians from Slovenia. It’s matured for 77 days --10 times the usual period for ale -- in American white oak casks, used the U.S. by Bourbon makers. It then rests for a further 30 days in a vessel called the marrying tun where ale and whisky fuse.

The beer is available in all leading stores at home and exported widely: it’s especially popular in Canada, where many people are of Scottish descent. It has won many awards and I&G received the Queen’s Award for Industry.

Other versions have appeared, including an oak-aged stout and beer aged in Irish whiskey casks.

Now Dougal Sharp has turned his attention to the island of Islay for his latest beer. Islay is called the Queen of the Hebrides and famous for single malt whiskies that have a pronounced character created by peat and an iodine note that comes from seaweed: seaweed, I hasten to stress, is not used in whisky production but its aroma fills the air.

Islay is home to several famous whisky makers, including Ardmore, Bowmore, Bruichladdich and Lagavulin. My particular favourite is Laphroaig with its pronounced peat and iodine character. It’s nicknamed Laughing Frog for those that struggle with the Gaelic name. Its character stems from malt being heated over peat fires.

I&G Laphroaig Islay Whisky Cask is 7.4 per cent and is aged in Bourbon casks for 10 weeks and then three weeks in Port casks. The beer that emerges from this lengthy maturation is flaming red with a big rocky head of foam. It has oak, vanilla, peat smoke and whisky on the aroma with smooth creamy malt, vanilla, oak and peat on the palate. The finish is long and bittersweet with continuing notes of smooth malt, oak, whisky and peat.

The beer, which comes in an attractive box, costs £6 a bottle and is on sale in selected branches of Sainsbury’s and Waitrose.

Slanté!