Beer packaging: aluminium cans or glass bottles?

The wherefrom team loves beer. We usually take some time to decide which beer to buy based on the type… lager, pale ale, sour beer? However, we’ve also been wondering which packaging would be the most eco choice. With 40% of the environmental impact of beer coming from the packaging used, it’s definitely important to understand which packaging is the least harmful. We wish we could give you a straightforward answer, but as is the case most of the time with sustainability, it’s kind of complex.
The easiest way to unpack the impact of the packaging is to look at its life cycle (i.e. from raw materials to end-of-life).
Raw materials and production
Glass
Glass is made from quarrying natural resources such as silica, sand and limestone. That means the ground or rock needs to be cut into making it a huge open-pit mine) in order to extract these materials. The mining of materials comes with a risk of water pollution and ecosystem disruption in surrounding areas. Furthermore, a significant amount of energy is necessary to power furnaces to produce glass once these materials are extracted.
Aluminium
Aluminium comes from the mineral called bauxite. It is extracted through heavy mining, which releases dust particles into the air causing air pollution, as well as water contamination, habitat destruction, soil erosion and even adverse health effects on miners and surrounding communities. Refining the bauxite in order to produce aluminium is also incredibly energy intensive - specifically requiring significant electricity and oil consumption.
Comparing the two
The production of glass requires more natural gas than aluminium, however the oil and electricity consumption for aluminium production make it so that aluminium’s global warming potential is 1.88 times higher than glass. Moreover, in terms of electricity consumption, aluminium requires approximately 12 times more than glass.
The verdict: Glass is better than aluminium for raw materials and production
Recycling
Glass
Glass is 100% recyclable and does not lose any value as it gets recycled. In Europe, the recycling rate for glass packaging was 76% in 2017. Producing new glass products from recycled material results in an energy saving of about 30% when compared with glass produced from virgin materials.
Aluminium
Similarly to glass, aluminium is 100% recyclable and does not lose its quality as it gets recycled. In Europe, the recycling rate for aluminium was 74.5% in 2017 (a 2.3% growth since 2016). When aluminium is recycled, it requires 95% LESS energy than when it is produced from raw materials. Furthermore, the recycling process only generates 5% of the greenhouse gas emissions produced from raw material production. As such, recycled aluminium saves around 3 million tons of greenhouse gas emissions.
Comparing the two
Recycling aluminium produces more energy savings than recycling glass in relation to the energy used for virgin production. However, it’s important to remember that aluminium requires much more energy than glass for raw production so it’s not necessarily more savings in absolute terms. Additionally, glass and aluminium recycling rates are very similar.
The verdict: Glass and aluminium are equally good for recycling
Transportation: weight and stackability
Glass
One 330ml bottle weighs 200g, making it quite heavy. Also, due to the fragility of glass, bottles require extra packaging to protect them from breakage during transportation.
Aluminium
An aluminium can of 330ml only weighs 11g - this is 189g lighter than glass. On top of that, due to the size and shape of aluminium cans, these can be packed more efficiently than glass.
Comparing the two
The efficiency in terms of space and lightweight properties of aluminium cans means that they can deliver 35% lower emissions than glass bottles per ounce.
The verdict: Aluminium is better than glass for transport
Final points

It’s hard to choose which packaging material is better. If an aluminium can is made of 100% recycled aluminium AND has been transported from outside of the UK, then it is probably better than a glass bottle that has been transported from outside of the UK. However, considering the higher greenhouse gas emissions and energy use of aluminium, glass is often a better choice.
The main takeaway here is to try and understand how much of the bottle or can you are about to purchase is made from recycled inputs and where it was produced. This can help you make the right decision.
On another note, a fun innovation that might be able to steal the show is biodegradable paper bottles that are sourced from sustainably managed forests. Carlsberg started the R&D on these paper bottles and are quite close to releasing them. The problem, for now, is that these bottles need a plastic (PET) or bio-plastic (PEF) lining to keep the beer from contaminating the paper. If they manage to make a completely bio-based bottle without polymers then this could be better than aluminium and glass in terms of production emissions, waste and weight.
Cheers to that!
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