The can v bottle debate

17th June 2019

The can v bottle debate

How do you (sustainably) drink your beer?

The can revALEution

In 2018, cans made up 25% of all craft beer sales in the UK. And according to Imbibe, 72% of all packaged beer is expected to be canned this year, compared to just 16% in 2016. Whilst cans may once have had a bad rep, breweries are shifting to canning and craft beer cans are taking over retail shelves.


Does canned beer taste better?

There’s nothing like fresh draught beer from your local pub or a brewery tap room (or currently the Waitrose Unpacked trial in Oxford). But for those times when you don’t have access to beer on tap and packaging is needed, there are logical arguments pointing to aluminium cans being the best option to preserve the quality of the beer.


Cans block out all UV light, massively reducing the likelihood of ‘skunked’ beer (where the flavour of the beer changes slightly). Glass allows light in, which breaks down certain hop compounds and alters the flavour of the beer – turning your tropical IPA into something far more temperate. The dark brown glass we use does a good job of blocking out a lot of UV rays, but cans are the ultimate winner.

Cans also stop oxygen getting in as they’re completely airtight. The bottling process sometimes lets oxygen in, which can result in over-oxidation, making for a beer with overtones of cardboard (not our favourite flavour).

Some drinkers notice a metallic taste from cans, and granted, if you’re sipping straight from the can, the metal will touch your lips. But the interior of aluminium drinks cans are lined with a water-based polymer that prevents contact with the metal.

Pouring into a glass will ensure the taste isn’t interfered with from either the can or bottle. It’s also the best way to explore the colour and aroma of the beer. After also, we taste with our eyes and noses too!


What’s the environmental case?

Well, there’s some pretty strong arguments both ways…

Life cycle analysis of beer identifies packaging as a key contributor to environmental impact (measured in Global Warming Potential): 42% for aluminium cans and 55% for glass bottles. Other impacts include water use and disposal, the raw ingredients chosen (namely whether malts and hops are organic and locally sourced) and the emissions from freight. As we contract brew, the main impact that we have control over is the packaging (and our partners at Wold Top do a fantastic job of managing the other impacts).

So we’ve looked at each stage of the life of packaging to compare aluminium cans and glass bottles, and picked our winners.

1. Materials

When thinking about the benefits of different packaging, it’s easy to skip forward to how recyclable the material is. But let’s start at the beginning with how we get the virgin materials.


Aluminium cans start life as the mineral bauxite. Mining bauxite requires heavy mining which destroys habitats, contaminates water supplies and contributes to soil erosion. The process also causes dust to be released, adding to air pollution. After extraction, a lot of energy is required to refine the bauxite, adding to aluminium’s environmental footprint.

Like aluminium, glass is also made from natural resources (silica, sand and limestone) which have to be quarried. Iron, sulfur and carbon is added to make the glass brown. These ingredients are naturally abundant. A significant amount of energy is required to power furnaces to produce glass, but it’s still simpler and less energy-intensive to produce. Aluminium requiring around 15x more energy.

For virgin materials, bottles win.

For both glass and aluminium, it’s important to maximise the amount of recycled content to minimise the demand for virgin materials.

Producing new aluminium cans is incredibly energy intensive. But, making a can out of recycled aluminium requires only 8% of the energy consumed by producing new aluminium. So maximising the recycled content of packaging can have a hugely positive impact.

As circular materials, bottles and cans are both winners if the recycled content is high.


2. Transportation


Transportation includes moving empty and filled containers from manufacturer to brewery, brewery to retailer, retailer to customer and drinker to the end of life waste treatment (hopefully reuse or recycling rather than landfill).

All of the packaging is produced relatively locally. Our glass bottles, made by Ardagh Group just 60 miles from our brewery partner. Our canning partner produces the cans in Braunstone (Leicester)

An individual glass 330ml bottle weighs about 200g compared to 11g for 330ml aluminium cans. We are looking at whether we can reduce the weight of our bottles (the lightest known being 135g). But bottles can break and require additional packaging to protect them in transit, adding to their weight. And lighter bottles may be even more prone to breakage.

Cans can be packed in more tightly thanks to the size and shape. According to the Aluminium Association, the space efficiency and reduced packaging weight of cans allows 35% lower emissions than glass bottles on a per ounce basis.

For transportation, cans win.


3. Storage

Energy and resource use for storing beer are also important to consider. As our beer is sterilised, it can be stored at ambient room temperatures and only needs refrigerating before serving.

Significantly, the space efficiency of cans allows more to be stacked onto shelves and fridges, and reduces the energy needed to cool cans before drinking.

For storage, cans win.


4. Recycling


Because it’s so energy intensive and environmentally degrading to extract virgin materials, we want to use recycled materials as much as possible.

Glass bottles can be melted down to make new packaging indefinitely, with no loss of quality. Aluminium can also be recycled again and again, without losing its material characteristics. Both are great circular materials.

In the UK, approximately 72% of aluminium cans are recycled and 67.7% of glass is recycled. This varies due to different rules on household recycling across the country, and changes in our behaviour at different times. This variability and other market conditions means that the recycled content of cans and bottles fluctuates

For recycling, both cans and bottles are winners.


The verdict

Drinkers should be able to choose the most sustainably brewed beer in the packaging that best suits them. We want to give people more ways to fight food waste and do their bit for the planet.

The most environmentally friendly way to enjoy a beer is to bypass packaging completely and drink beer fresh on draught. For packaged beer, aluminium cans and glass bottles both have their positives, and whilst we haven’t yet completed a full lifecycle analysis, cans are edging ahead*.

As Toast is already available in kegs and bottles, we’re crowdfunding for the first canning of our planet saving beer. And we’re offering beery rewards – it’s like pre-buying beer, or pre-investing in the planet. CAN you help us hit our target? Pledge your support and scoop up rewards at to show craft beer CAN fight food waste.

* Once we have set up operations in cans, we’ll complete a full lifecycle analysis to share





What percentage of your bottles and cans are made from recycled glass and aluminium?

We currently buy glass bottles with our partner brewery from Ardagh Group, and will be using aluminium cans produced by Crown Bevcan

It’s not possible to measure the recycled content because recycled aluminium or glass is identical to the virgin materials. For example, Crown buys aluminium sheets from metal producers, who use a mix of virgin and recycled metal. 

However, there is a market incentive to use recycled materials and so producers will maximise its content. Glass and aluminium are permanent materials and can be recycled again and again without losing their properties. The recycling process and infrastructure is efficient and economical, and less energy is needed for recycled materials (95% less in the case of aluminium) . Scrap metal is particularly valuable because it can be used for lots of things (another beer can, a car, a building…). 

So, wherever these materials can be recovered, they are, and very little goes to waste. However, the limiting factor is how much recycled material is available i.e. how much gets recycled in the first place, compared to how much is needed.

Buying glass or aluminium on the basis of high recycled content does not stimulate further recycling. What is important, is that we encourage people to recycle. In the UK, approximately 72% of aluminium cans are recycled and 67.7% of glass is recycled. Increasing these rates will raise recycling rates and reduce the need for virgin materials.

(Plastics are a different story. Stipulating the recycled content for plastics is done to stimulate recycling and the use of recycled plastics. Plastic can only be recycled a certain number of times and each time it loses some properties until it cannot be used anymore. So recycled plastic can be more expensive than virgin plastic.)

Find out what can be recycled where you live:


What about reusable packaging?

We supply our beer in reusable steel kegs from Kegstar so that it can be sold on draught in pubs, bars and events. We are currently the only brewery involved in the Waitrose Unpacked trial in Oxford, offering beer in re-fillable growlers. The trial will measure whether shoppers are prepared to change the way they buy everything from dry goods, fruit and veg to wine and beer.

We are a very small beer company with a wide national customer base. This means it wouldn’t be possible for us to operate a glass bottle collection and reuse service alone, although we are beginning conversations with others about how this could work if we do it together. It would involve making changes to the bottles such as making the glass thicker and less prone to breakage during transportation and cleaning. This means we’d have to use more glass and it would make the bottles heavier, with implications for the carbon footprint. So there’s not a simple answer!


What about the problem of littering?

Littering is a problem for all packaging, regardless of the material it is made of. The availability of bins and the ease of recycling is an important factor, as is education, but national policy is needed to drive real behaviour change. 

We support the introduction of a bottle deposit return scheme in the UK that makes retailers responsible for properly recycling (or supporting reuse) of the containers. The consultation closed in May and we’re waiting for the government’s response. Deposit return schemes (DRS) have reduced littering and increased recycling rates to more than 90% in other countries. 


What material is your label made of and is it recyclable?

Both bottles and cans have a label that is made with Polypropylene (PP) plastic. However, we plan to get to a scale of can production within 6 months that will mean we can move to printed cans (i.e. no labels). 

Polypropylene labels are fairly typical for craft brewers. Bottling and canning lines can be wet and drips of beer during filling can damage paper labels. Condensation caused by moving packaged beer from ambient to chilled environments can result in condensation, and people like to be able to put beer directly into ice buckets. These wet conditions can damage labels, often resulting in waste of the container and the beer.

Our labelling partner, Label Express, has completed an extensive study on the recyclability of packaging with labels.



When cans go to aluminium recycling facilities, the label is separated from the aluminium flow. The aluminium is endlessly recyclable, but the label is a burden for them. That’s because they’re paying by weight for cans that include non-aluminium materials, and then they’re having to treat this material. The recycling facility will choose what to do with the label: off-site plastic recycling, energy from waste generation or incineration.

Novelis Recycling, the World’s largest recycler of used aluminium beverage cans, provides guidelines to design for recyclability. That includes minimising the non-aluminium content of the packaging – they would prefer painted cans over labels of any kind. However, they understand why labels are being used for start-up product lines.

Novelis also recommend that labels should be as light and easy to remove as possible. This includes designing labels that drinkers can remove and put into their household plastic recycling, and making sure that communications on the label make this clear.



It’s challenging to remove self-adhesive labels during the glass recycling process. All non-glass substances are separated out and tend to go to landfill because they’re contaminated with glass (and so that glass is also wasted rather than being recycled).

The industry is currently working on a label that can “float off”. This would reduce glass waste and allow the label itself to be recycled. We are working with Label Express to monitor these developments.


What we’re doing

We will be launching with a fairly small production run of labelled cans to test out the market. We know the popularity of cans is growing fast, and the supermarkets are shifting to cans, so we’re confident they will be well received. We’ll then invest in printed cans – we need to commit to about 1 year of stock so it’s important that we get this decision right!

We encourage all our customers to recycle their cans and bottles, and are adding the recycling symbol to our packaging to make sure everyone knows (and is reminded). Removing the label will allow that to be recycled too – PP is a commonly recycled plastic (but do check your local council’s rules here). However the container will still be recycled even if it isn’t removed.


What material is the can lined with?

The inside of aluminium drinks cans are lined with epoxy based coatings. This performs a number of jobs, including maintaining the quality and taste of the contents over a fairly long life and preventing the contents corroding the metal. Beer cans have a very thin coating to prevent the carbon dioxide escaping – the coating smoothes out the surface of the metal, so that the gas has no microbumps from which to propagate.

The coating is a type of plastic that remains after the aluminium is dissolved. We don’t know if this can be recycled but is certainly poses an issue for the recycling industry. We are finding out more and will update.

We’ll be using standard aluminium cans for our initial run of labelled cans. However, our canning partner is currently negotiating with Crown for our move to printed cans in approximately six months time. We will be pushing for the best option.

Crown performed tests You can find more information here.