Beer Cans vs Bottles: Which Are Better For The Environment?

Now that the most popular styles of Small Beer are available in cans as well as bottles, we wanted to explain our thinking behind the decision and promote more discourse around a complex environmental issue.

When we first started the Small Beer journey, we spent long hours researching and debating the pros and cons of packaging our beers into cans and bottles. Finally, we came to the conclusion that bottles were the more environmentally friendly option for us. We felt confident that we had gathered strong enough evidence to buck the trend in the UK and establish what we knew to be right by the planet.

Five years later, we have decided to reveal our thinking behind choosing bottles over cans and perhaps more pertinently, explain why we have decided that now is the right time to offer three of our beers in aluminium cans.

We have always been huge fans of draught beer and wherever possible, we love to offer and enjoy our beer on tap. However, there are plenty of occasions where that just isn’t possible: the midweek fridge staple, the Sunday BBQ or a simple sundowner in the park. For those occasions, we knew we needed to opt for a can or bottle. Today’s bottle and can filling technologies mean that both offer exceptional quality and each lends itself better to certain occasions. But how about our quest for their true environmental impact: how do cans compare to bottles?

Before we start to unpick the environmental debate around canning and bottling beer, it’s worth acknowledging one thing: this is a big topic. To give you an idea of just how big, the range of factors that need to be considered include, but are by no means limited to: primary energy demand, water demand, land use, labour and people impacts, biodiversity, abiotic depletion, acidification, eutrophication, human, terrestrial and aquatic ecotoxicity, air pollution, ozone depletion and generation of photochemical oxidants.

While we want to assess the bigger picture, we won’t be able to touch on all of the above. Instead, we have aimed to provide a balanced and impartial review of current sources, a view into the future and we’ll wrap up with how we’ve made the choices we’ve made at Small Beer.

A number of studies have sought to put an end to the question of the environmental impact of cans versus bottles. The definitive means to evaluate the impact is to assess the full lifetime of each material from ‘cradle to grave’ using a Life Cycle Assessment or LCA for short. Every LCA makes assumptions and given the variation in global supply chains, availability of source materials and market conditions, the conclusions drawn vary widely.

To summarise the LCA in broad brush strokes, we need to understand the flow of materials. As the name suggests, we’re looking at a continuous loop of recycled materials, with input of raw materials at one end and losses at the other. As you would expect, recycling both cans and bottles is more efficient than producing them from scratch. Another piece of good news: unlike plastics, both are virtually infinitely recyclable.

Let's pause briefly to consider deposit return schemes: until the 1980s, British breweries encouraged the use of returnable bottles which could be washed and refilled. The introduction of non-returnable bottles in the UK saw the weight of the average bottle cut to less than a quarter and reduced the need for energy and chemical intensive bottle washing facilities. Nevertheless, the energy demand for making new bottles typically outweighs this impact and a full returnable bottle scheme as exists today in Germany and Denmark can be beneficial from an environmental perspective, particularly if standardised bottles are used. Reintroducing such a scheme in the UK requires large scale infrastructure change, which is something that Small Beer fully supports.

Post consumer recycling rates in the UK tell us that as of 2021, three out of four cans and bottles were recycled. We’re seeing a continuous upward trend in these rates and with a deposit return scheme planned for the UK in the near future, we’re getting ever closer to closing the recycling gap.

The main differences between bottles and cans arise from two key sections of the cycle: the container’s useful life from production to consumption and the sourcing of raw materials.

The UK's infatuation with David Attenborough helps to remind us of our breakthrough learnings from early space travel: we live on a beautiful planet of blue and green (Let’s keep it that way, shall we?!). It’s often easy to forget therefore that beneath the surface, earth is composed for the most part of molten iron at temperatures that would burn you to a crisp in seconds. Thankfully, that part is completely inaccessible to all but science fiction. Let’s look at the 10 miles or so directly beneath our feet which are accessible to man made machinery: the earth’s crust.

After oxygen, silica and aluminium are the most abundant chemical elements that make up the earth’s crust. Silica in the form of quartz sand can be melted to form glass bottles, while aluminium is the main component of virtually all drinks cans used today.

The major difference in extracting the two elements is that sand is abundant the world over, whereas aluminium is concentrated in defined regions of the world in places such as Australia, Guinea, China and Brazil.

Aluminium is mined in the form of bauxite ore in destructive strip mines, requiring vast amounts of electrical energy to smelt the ore which in many instances is generated locally in hydroelectric dams. The energy demand has been well reported and documented in the abovementioned LCA’s. From our research, what has typically not been considered in these same reports are the unintended consequences of habitat loss and displacement of indigenous peoples associated with building dams. The dams have also been reported to silt up before their intended lifetime has been achieved which further exacerbates the impact.

The quartz sand required to make glass is more widely abundant, meaning that it can be sourced closer to the glass manufacturing plant. There’s no doubt that melting glass in a furnace is extremely energy intensive and to this day the majority of furnaces are heated with non-renewable energy sources, but the general outcome of the LCA’s is that the negative effects of sourcing and smelting bauxite ore for cans far outweigh those of the sand required for bottles.

From here on out, cans beat bottles on virtually every front:

Cans are significantly lighter than bottles, reducing overall resource consumption, emissions from transport at every stage from manufacture to consumption and disposal. A typical 330ml can weighs 10g, with can manufacturers continually working to reduce weight whilst maintaining integrity. A typical bottle of the same volume weighs upwards of 220g, which is 22 times more!

Cans hold more volume than bottles, hands down. They stack neatly in slabs for efficient transport and their shape means that you get a lot more liquid per pallet than with bottles due to the space taken up by the thickness of the glass and the air gap around the neck of the bottle. Similar to with the weight above, this means fewer emissions from transport.

As much as we do our best to protect cans and bottles, they do occasionally get damaged in transit. Empty cans are far more likely to be damaged than empty bottles. More troubling, of course, is damage to a can or bottle once it has been filled with beer. Cans tend to fare better than bottles once they’ve been filled as they’re flexible rather than brittle.

In traditional retail, environment damage is minimised by efficient packaging and palletisation. With the move to e-commerce sales particularly in the post-pandemic world, breakage rates are higher. Right now, secondary packaging materials like recycled cardboard has never been so in demand or so high in price. Just because cardboard is made from trees, it does not excuse it from its contribution to global GHG emissions.

Glass itself is a great food contact material. It’s clean, sterile and a relatively impermeable barrier to oxygen and UV light. It does however require a closure, with beer this typically comprises a lacquered tin free steel crown cap with a oleofine liner, each material with its own environmental baggage.

Aluminium on the other hand is a poor food contact material. The naturally low pH of beer and soft drinks corrode aluminium, so all cans have a thin plastic liner inside which acts as a barrier between the can and the liquid. On this front, we believe cans fall down. It’s a little known fact which the can industry likes to gloss over with its slogan ‘metal recycles forever’. Well sure it does, but the plastic inside is burnt off in the process, and when were you going to tell us that part?

Cans can be printed on directly, though the minimum print runs of 150,000 cans exclude most small producers. The lacquer itself is burnt off in the recycling process just like the plastic liner, so it’s not without its woes.

Labelling cans can be problematic depending on the substrate used. Contrary to what one might expect, a paper label on an aluminium can is by far the worst option as it renders the can unrecyclable. Aluminium furnaces will reject cans labelled with paper as the paper produces ash which contaminates the recyclate. Plastic labels are accepted but bear the impact of burning plastic. Anecdotally the calorific value delivered by plastic liners and labels provides sufficient heat to melt the aluminium without requiring further use of gas to maintain the furnace temperature. As such, one might argue that the fossil fuel captured in that label is merely displacing that in the primary energy source. In this day and age, pitting one fossil fuel against another is an argument for fossils.

It’s much the same story for bottles. There is a further complication in that certain adhesives can mean that the recycled glass cullet cannot be effectively separated from the label which would again contaminate the furnace.

(This topic is a minefield and one which we are in the process of developing a really neat answer to…watch this space!!)

Recycling systems work best when there aren’t large shifts in demand from one material to another. If the demand for a material remains stable, the recycling rate remains high and the material is not degraded by the recycling process, the system remains stable with little additional input.

The past five years have seen a huge worldwide shift in consumer demand. Despite being easily and successfully recycled, our demand for PET plastic bottles is on a steady decline in favour of aluminium due to the war on plastic. As a result, the price for PET recyclate has dropped meaning that it’s no longer so commercially attractive to process PET back into the recycling stream. Meanwhile, demand for aluminium has skyrocketed due to a boom in beer and other canned beverages as well as in electric cars and consumer electronics. As such, aluminium recyclate has no chance of plugging the gap, so more bauxite ore is being mined to make up for it.  

We’ve alluded to a few elements along the way that are particular to Small Beer and pertinent in understanding the choices we have made along the way.

One of those is the specific design of our bottle which helps us to achieve a lower footprint compared to a can. Despite holding more beer than a typical 330ml long neck bottle, our Small Beer bottles are 20% lighter (180g vs. the typical 220g) and their shorter necks allow for 40% more beer to fit on a pallet, further reducing our carbon footprint with each delivery versus other beers.

To summarise the journey through the LCA, Small Beer’s uniquely shaped bottles still have the upper hand on cans due to the high impact of bauxite mining for aluminium and the shift in demand away from plastics towards aluminium. As the UK recycling rate continues to improve and the growth in aluminium demand settles, we’ll hopefully reach a stage when recycled aluminium stock outweighs demand, at which point the argument will likely swing towards Small Beer cans.

As such, although we predominantly fill and sell bottles, we now can our most popular beers as well to allow our customers to make the most of those moments when a can is much better suited, such as festivals and other outdoor occasions. You can rest assured that whether you buy your Small Beer in cans or bottles, you are doing your bit for the planet by buying beer that has a lower impact on the environment, which is backed up by our B-Corp status. We ask one thing of you in support: whether you’re buying in bottles or cans, please always ensure you recycle your empty container.

As we said at the beginning, this is a big topic with no easy answer. At Small Beer, we’ve taken our time to take a step back, look at the bigger picture and make a thoughtfully considered choice of how we can sell our beer in a way that we can be proud of. We hope that this has helped shed some light on something that is not as black and white as it first appears and that next time you reach for a cold, crisp beer, you’ll feel empowered to decide which format is best for you.