Wooden barrels are what make the magic happen in your favorite bottle of whisky. They’re also the source of a long-standing problem in the spirits industry: They leak. A lot.
At Bacardi Limited, the world’s largest privately held spirits company, barrel leakage is a massive headache. Consider the company’s Dewar’s blended Scotch whisky brand (just one of the dozens it owns). Most of the time, Dewar’s will have over 100 warehouses full of aging barrels of whisky, 25,000 casks in each one. Barrels will mature for three to 12 years, and according to Angus Holmes, Bacardi’s whisky category director, many of those barrels will develop a leak at some point in their life.
That’s not great for business, says Holmes. “How do we make sure that when we come to get that cask, it’s got as much whisky in it as possible?”
Given the imperative to find so-called leakers before a decade has come and gone—and taken all the whisky with it—Bacardi engaged the National Manufacturing Institute Scotland. NMIS was presented with the problem, and came up with a surprising solution: Why not adopt a robotic dog?
Andrew Hamilton, head of the Digital Process Manufacturing Centre for NMIS, says the group’s first suggestion was that Dewar’s might try a Boston Dynamics Spot robot which could roam the warehouse on the prowl for leaking barrels.
But to be a truly effective hunter, the robot dog would need to adopt one of the actual canine family’s most well-honed skills: an elevated sense of smell.
Vapor Trails
There are two kinds of leaks: liquid spilling or seeping out of the barrel, and loss of liquid through vapor evaporation. A barrel leaking liquid is fairly easy to identify, but if it’s losing more than it should through evaporation, that’s harder to suss out.
Evaporation is an expected part of whisky maturation, “the angel’s share” being a well-understood phenomenon that is widely considered a key part of a whisky’s evolution. In Scotland, the angels take about 2 percent of a cask’s volume each year, and while some enterprising distillers have attempted to deny the angels their due through experimental techniques like covering barrels in plastic wrap, by and large distillers are happy to give a little whisky back to the universe as a cost of doing business.
