Now the distillery is supplying Celtic Renewables with feedstock for an ongoing pilot project that will turn the organic matter into useful industrial alcohols including biobutanol, which supporters say is superior to the world's current most popular biofuel: ethanol. Disposing of it costs the company £250,000 ($375,000) a year. Tullibardine, a distillery in Blackford, about 50 miles northwest of Edinburgh, annually produces 2 million liters (528,344 gallons) of pot ale and 6,500 metric tons of draff. Scotch Whisky Association spokeswoman Rosemary Gallagher said the industry is very open to the idea: 'We will follow Celtic Renewables' progress with interest.' (See quiz: ' What You Don't Know About Biofuel.') 'One man's waste is another man's gold,' he said. If Celtic Renewables meets its goal of turning a 'high percentage' of all that waste into biobutanol, Tangney reckons he can create a £60 million ($90 million) biofuels industry. 'They have a major disposal problem,' said Martin Tangney, Celtic Renewables founder and president. Getting rid of all that leftover muck hits manufacturers' bottom lines.

Scotland's distillers churn out 1.6 billion liters (422.7 million gallons) of pot ale and 500,000 metric tons of draff annually. (National Geographic uses the spelling 'whiskey' to refer to the spirit in general but 'whisky' when referring specifically to Scotch or Canadian whisky.) Most of what remains is draff, the residue of the grains of barley and pot ale, a copper-laden liquid. In a distillery, only 10 percent of what flows out of a still is future whisky.

Edinburgh-based Celtic Renewables is resurrecting a once popular, but almost forgotten, fermentation process that it says can turn the dregs of Scotland's £4 billion ($6 billion) whisky-making industry into many millions of gallons of clean, renewable biofuel. A Scottish energy start-up aims to prove that cars and booze aren't necessarily a dangerous mix-as long as the hooch is poured into a fuel tank and not down a driver's throat.

Whiskey a go go