Stirling Distillery has partnered with Heriot-Watt University's International Centre for Brewing and Distilling (ICBD) and its Institute of Chemical Sciences (ICS) for a project examining how whisky responds when stored in aluminium bottles, as an alternative to glass.
Stirling Distillery began production of its own new make in 2023 and expects to release its first mature whisky in 2027. Kathryn Holm, head of communications and marketing, said the goal is to "make our distillery as sustainable as possible".
She explained: "Glass has long been central to whisky’s image; it’s weighty, and evokes the craftsmanship of the spirit. But it is also heavy to transport and relies on high recycling rates to reduce its environmental impact. Aluminium is lighter and widely recycled, so I asked the experts to investigate whether it’s a viable alternative."
Aluminium bottles are already in use by brands in other wine and spirits categories, including wine, gin, and vodka, but the material is new territory for whisky producers. Different alternatives to heavy glass have been explored in the Scotch industry, such as Johnnie Walker's trials of paper-based bottles and lighter glass.
Dr Dave Ellis and his student Charlotte York are carrying out the research at the ICBD. Under the project, aluminium bottles filled with Stirling's spirit are tested over several months using nuclear magnetic resonance spectroscopy, which identifies the composition of a substance, and inductively coupled plasma mass spectrometry, to detect metal levels in the liquids.
Dr Ellis said: "We know that certain organic acids naturally present in matured whisky can react with aluminium, which can lead to aluminium entering the liquid." Currently, tests have shown that the level of aluminium entering the metal is "well above what would be considered acceptable for drinking water", and some compounds found in matured whisky, such as gallic acid, were "reduced or removed after prolonged contact with aluminium".
The ICBD's Professor Annie Hill said: "Any innovation has to respect the craft of whisky making while meeting the highest standards of safety. The aluminium cans we buy pulses and soup in all have liners to protect the contents from metal contamination.
"In this case, the liner within the can wasn’t sufficient to prevent aluminium from passing into the spirit. The next stage of this research would be to find a liner that can withstand high alcohol levels for a prolonged period of time without degrading."
Professor Hill and her student Andrew Marr ran sensory testing under the project. In the trials, participants were unable to tell the difference between whisky stored in aluminium from that which was stored in glass. "So the changes detected in the laboratory didn't translate into differences in aroma," said Professor Hill.
Holm said that Stirling will share the work with the Scotch whisky industry, which has been working to meet net-zero goals set by the Scotch Whisky Association in 2021.
Holm said: "We are not suggesting glass disappears tomorrow. But offering customers a lower-carbon option for a premium product is something worth exploring. As a small distillery, we can help start that conversation."
