Scotland’s smallest whisky distillery also hopes to be one of the most innovative in time for its first batch’s debut. But with only around two years until Sterling Distillery’s inaugural liquor matures, it remains to be seen if the company can ditch traditional glass bottles for a material associated more with cheap beer than fine whisky—aluminum.
Any serious distillery uses glass bottles for the good stuff. The reason is as much about aesthetics as it is about chemistry. From a psychological standpoint, the hefty, translucent glass implies the painstaking artisanal craft required to produce an elevated batch of whisky (the “whiskey” spelling is generally only used by Irish and American distillers). The material also is guaranteed to not interact with a whisky’s delicate flavor profile, that can only be achieved after years or even decades of aging.
There are serious sustainability problems with the industry’s reliance on glass. Most glass manufacturing still requires vast amounts of energy at a major environmental cost. What’s more, all those heavy whisky bottles then ramp up pollution and other problems as they’re transported around the world. Once a bottle is finally empty, recycling is harder than you might think. Manufacturers have long offered popular drinks—both with and without alcohol—in much more sustainable aluminum containers. So why haven’t distilleries made the leap?
Sterling Distillery recently approached chemical scientists at Scotland’s Heriot-Watt University to provide some answers. Researchers spent months analyzing how aluminum can affect the liquor’s chemical composition and flavor profile. Using nuclear magnetic resonance spectroscopy, the team first measured how alcohol and metal atoms interacted when whisky is stored in aluminum. While they found that contact with the metal often reduced or eliminated important compounds like gallic acid, volunteer taste testers didn’t differentiate between whisky housed in glass and aluminum bottles.
From there, the team used plasma mass spectrometry to measure the actual metal levels in the whisky. The small samples used for the taste test were comparatively safe, but they soon determined a potentially major branding issue: no one wants metal poisoning from their whisky dram.
“We know that certain organic acids naturally present in matured whisky can react with aluminum, which can lead to aluminum entering the liquid,” Dave Ellis, a chemist at Heriot-Watt University, said in a statement. “If we stir samples with aluminum metal, the levels were well above what would be considered acceptable for drinking water.”
The reason this isn’t an issue in other aluminum containers like soup cans is due to their linings. For decades, soup cans and other products featured a transparent coating as much as 10 micrometers thick made from various epoxy resins and Bisphenol A (BPA) plastics. Because BPA plastic has plenty of its own health and environmental issues, industries have slowly switched to alternative liners—but it remains to be seen if any of them can hold up to a potent whisky.
“Any innovation has to respect the craft of whisky making while meeting the highest standards of safety,” added Annie Hill, a researcher at Heriot-Watt’s International Center for Brewing and Distilling. “In this case, the liner within the can wasn’t sufficient to prevent aluminum from passing into the spirit.
The team added that aluminum whisky bottles aren’t impossible in the future. However, distillers and scientists still need to find a lining that could withstand years—and sometimes decades—on a whisky aficionado’s shelf. Sterling Distillery wants to have aluminum bottling ready for the debut of its first matured whisky in 2027, so it still has some time to locate a liner. But if there’s one thing whisky teaches you, it’s that you can’t rush a good thing.
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