In a collaboration that brings together craft distilling and applied materials science, Professor Annie Hill of Heriot-Watt University is leading a research effort to evaluate whether aluminium could replace glass in whisky bottling. Working with Stirling Distillery and colleagues from the university’s School of Engineering and Physical Sciences, the team is examining the environmental case for lighter packaging alongside the chemical and safety implications of storing high-strength spirits in metal containers.
Sarkar, S., Ash, B., Wu, Y., Boechler, N., Shankar, S., & Mao, X. (2025). Mechanochemical Feedback Drives Complex Inertial Dynamics in Active Solids. Physical Review Letters, 135(25), 258301. https://doi.org/10.1103/19rh-3whq
Glass has long defined the presentation of Scotch whisky. It is chemically stable, widely recyclable, and closely tied to the identity of premium spirits. However, it is energy-intensive to produce and relatively heavy to transport. Aluminium, by contrast, is lighter and benefits from well-established recycling streams. From a life-cycle perspective, reducing packaging weight could lower transport emissions, particularly for export markets where bottled spirits travel significant distances.
Professor Annie Hill of Heriot-Watt University stated,
“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.”
The scientific challenge lies in understanding how matured whisky behaves in prolonged contact with aluminium. To address this, researchers stored spirit supplied by Stirling Distillery in aluminium bottles and monitored it over several months. Analytical work was carried out using nuclear magnetic resonance spectroscopy to track changes in organic compounds and inductively coupled plasma mass spectrometry to measure trace metal levels in the liquid.
The data showed that certain organic acids that develop during cask maturation, including gallic acid, can react with aluminium surfaces. In controlled laboratory conditions where spirit was stirred directly with aluminium metal, aluminium concentrations in the liquid rose beyond levels considered acceptable for drinking water. These results indicate that unmanaged contact between whisky and bare aluminium would not meet safety standards. The reactions were less pronounced in newly distilled spirit, which contains a different chemical profile before ageing.
Alongside the chemical analysis, the team conducted sensory evaluations to determine whether measurable changes translated into perceptible differences. Panelists were unable to reliably distinguish between whisky stored in aluminium and that stored in glass. While this suggests that short-term storage did not produce noticeable flavour deviations, sensory neutrality alone is not sufficient if trace metal migration occurs over longer periods.
The role of internal liners has therefore become central to the next phase of research. Aluminium beverage containers typically rely on polymer coatings to prevent direct contact between liquid and metal. In the initial trials, available liners were not fully resistant to prolonged exposure to high alcohol concentrations. The researchers are now exploring alternative barrier materials capable of maintaining integrity over extended storage without degrading or allowing metal transfer.
For the whisky industry, which operates within strict regulatory frameworks and long maturation cycles, any packaging change must satisfy safety, durability, and brand considerations. Stirling Distillery has indicated that the project is exploratory rather than a replacement mandate. The intention is to assess whether a lower-carbon packaging option could be offered alongside traditional glass, particularly as producers face increasing pressure to reduce environmental impact.
From an engineering perspective, the study highlights the complexity of substituting materials in established consumer products. Weight reduction and recyclability are important sustainability metrics, but they must be balanced against chemical compatibility and long-term containment performance. Whether aluminium can meet those requirements for high-proof spirits remains an open technical question, one that will depend on advances in barrier coatings as much as on the metal itself.
Adrian graduated with a Masters Degree (1st Class Honours) in Chemical Engineering from Chester University along with Harris. His master’s research aimed to develop a standardadised clean water oxygenation transfer procedure to test bubble diffusers that are currently used in the wastewater industry commercial market. He has also undergone placments in both US and China primarely focused within the R&D department and is an associate member of the Institute of Chemical Engineers (IChemE).
