A hard cask to master

John Roberts has an ambition to develop a "fine beer" sector similar to fine wine, appealing to connoisseurs prepared to pay a little extra for beer brewed with special skill and passion.

Roberts is the managing director of Fuller's Beer Company, the brewing arm of Fuller's of Chiswick, in west London. He has been encouraged in his ambition by the success of such brands as Fuller's Vintage Ale and Gale's Prize Old Ale, and last week launched a remarkable new beer to add to his collection.

It's called Fuller's Brewer's Reserve and is the latest addition to the sector known officially as oak-aged beer, but dubbed by many "whisky beer". The stage was set by Innis & Gunn in Scotland who launched their Oak Aged Beer to great success and acclaim and prompted several other Scottish brewers, including Harviestoun, to follow suit with beers matured in whisky casks.

The new Fuller's beer is the result of four years of dogged research by Fuller's head brewer, John Keeling. He had noted the success of Innis & Gunn's beer at the same time as he was studying the way in which his bottle-conditioned Vintage Ale changed and matured over the years. He visited some malt-whisky distilleries in Scotland and noticed to his amazement that the distillers broke up and threw away casks that had been used to mature 30-year-old malts.

"I thought that whisky and barley wine would work together," Keeling told me. "So I arranged to get some casks from Scotland, filled them with beer and left them for three to four months."

Distillers use casks that have previously been used to age port, sherry and American Bourbon whiskey. Keeling noticed that after an ageing period, the beer in port and sherry casks was turning sour, but the beer in Bourbon containers was maturing well. As a result he decided, with the support of John Roberts, to go ahead and produce a commercial beer aged in Bourbon casks. Fired with enthusiasm, he bought 35 redundant casks from a Scottish single-malt distiller, but thought it might be a good idea to speak to HM Revenue & Customs, which levies duty on beer, to make sure everything was tickety-boo.

The excise people told him they would be satisfied if additional alcohol was the result of secondary fermentation in the whisky casks, not from any drops of spirit locked in the wood. Any increase in strength could not be more than 1% or 2%, they added. Keeling was cheerfully working to these parameters when the excise officers phoned back and dropped a bombshell.

They had done further research and discovered an Act of 1835 that outlawed "grogging". This was a form of smuggling: whisky and other spirits such as gin, rum and brandy were illegally added to beer to make it stronger, but without paying the additional duty. The excise people told Keeling that if his beer increased in strength by just 0.1% he would have to pay spirit duty.

Keeling was horrified. By adding Fuller's 8.5% Golden Pride barley wine to the whisky casks the strength had risen to 12%, well outside the excise guidelines. The brewery was still keen to produce an oak-aged beer, and Keeling told Revenue & Customs that Fuller's was prepared to buy a spirit licence. The debate then entered the world of farce.

"If you want a spirit licence, you will have to own a still," the excise people told Keeling. "OK, how much is a still?" he asked. "Ah," replied the tax men, "it's illegal for a brewer to own a still."

HMRC battle​

It seemed the project — if you'll pardon the pun — was still-born. But John Keeling is a hard brewer to keep down. He developed a cunning plan that he hoped might satisfy the excise men. He told them he would produce a beer that was 7.7% abv. This would be the result of blending three of his beers — 1845, Golden Pride and ESB Export — with a strength of 10% abv. At the end of the ageing period in cask, he would add fresh ESB and bring the strength down to 7.7%. He put this proposal to Revenue & Customs and crossed his fingers. Eventually, the answer came back: "That's all right — it's legal."

The result is Brewer's Reserve No 1, a bottle-conditioned beer matured for more than 500 days in whisky casks. It has orange fruit on the aroma — typical of Fuller's stronger beers — with a pronounced whisky note as it warms in the glass. Hop bitterness builds in the mouth, balancing tart fruit and warming whisky. The finish starts bittersweet, but becomes dry, with a good hop character balancing fruit and whisky.

It's a delicious and intriguing beer: four beers blended in whisky casks that started life in the United States to mature Bourbon whiskey. The world of beer becomes ever more fascinating.

The beer, packaged in an attractive box, will cost £4.99. You won't find it on shelves alongside slabs of cheap lager. John Roberts is right: beer of this quality and distinction deserves to be treated as seriously as the finest of wines.