STIRLING Distillery has partnered with Heriot-Watt University to find out if aluminium could replace glass bottles for its Scotch whisky.
Working with experts from the school of engineering and physical sciences, the project will investigate how whisky behaves when stored in aluminium rather than traditional glass bottles.
Kathryn Holm, of Stirling Distillery, initiated the project. She said, “We want to make our distillery as sustainable as possible ahead of our first mature whisky being released in 2027. The whisky industry is looking at lots of ways to minimise its footprint. We’ve already undertaken a range of sustainability measures – packaging is one of the remaining areas where we can innovate and make an impact.
“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.”
At Heriot-Watt, the researchers from the ICBD and Institute of Chemical Sciences combined advanced chemistry with sensory tests to assess whether aluminium interacts chemically with whisky in a way that alters its flavour or, most importantly, raises safety concerns.
Spirit supplied by Stirling Distillery was placed in aluminium bottles and tested over several months.
Dr Dave Ellis and his student, Charlotte York, tested the spirit using nuclear magnetic resonance spectroscopy. The technique uses a powerful magnet combined with radio frequency waves to identify what a substance is made of by measuring how its atoms respond, and inductively coupled plasma mass spectrometry, which detects levels of metals in liquids.
Dave said, “We know that certain organic acids naturally present in matured whisky can react with aluminium, which can lead to aluminium entering the liquid. If we stir samples with aluminium metal, the levels were well above what would be considered acceptable for drinking water.”
The chemistry showed that compounds such as gallic acid, which develop during whisky maturation, were reduced or removed after prolonged contact with aluminium. These reactions were much less pronounced in new make spirit, which has not yet developed the same chemical profile.
Professor Annie Hill, of Heriot-Watt’s ICBD, said this highlighted why caution was essential. She continued, “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 oversaw the sensory testing of the whisky stored in aluminium, carried out by her student Andrew Marr.
“Panellists couldn’t distinguish between whisky stored in aluminium from whisky stored in glass. So the changes detected in the laboratory didn’t translate into differences in aroma. That’s great news – if we can find an effective liner.”
Kathryn Holm said the work would be shared with the wider industry, which is under growing pressure to meet Scotland’s net zero targets while maintaining strict regulatory standards.
She 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.”
