No Dan, it's the other way round, an ex-bourbon cask gets the ale first and then goes on to finish Grants Ale Cask Blend. From their (http://www.innisandgunn.com/index.html
Innis & Gunn beer was discovered completely by accident...
Back in 2002, leading whisky producer William Grant & Sons decided to make ale-finished whisky. Renowned Brewer, Dougal Sharp, was commissioned to formulate a special beer to impart a smooth, beery character to the bourbon barrels. This would in turn flavour the maturing whisky (port and sherry finished whiskies are made in the same way).
A unique, malty, Scottish Beer was produced. This was placed in the barrels for 30 days, before being discarded to make room for the whisky.
The Ale Cask Whisky was a real success, and it was only many months later, after thousands of gallons of beer had been thrown away, that Dougal received a call that would change everything.
The Distillery manager told him that workers emptying the barrels were filling empty lemonade bottles with the beer… They had discovered something that no one else had even thought about - the beer had been completely transformed by its time in the oak!
The beer was then tasted by industry experts and scored an unheard of 9 out of 9! In August 2003, Innis & Gunn Oak Aged Beer was launched to a thirsty world, and no one has looked back since.
And the name Innis & Gunn? It’s the middle names of the founder, Dougal and his brother Neil.