In previous articles in this series, brewing experts have shared common mistakes to avoid when setting up a canning line, and the business considerations that go into choosing between bottles and cans. This week, Will North looks at the carbon and environmental factors you should consider.

The choice between bottles and cans should be informed by a range of environmental considerations. These include the carbon impact of glass and aluminium extraction and converting, their transport, and their ability to be recycled. The lightness and recyclability of metal would suggest a clear winner, but there are nuances to be considered.

Persuading customers

Toast launched with circularity a bedrock of its business: its goal is to turn discarded bread crusts into usable products, including beer. One of its key early markets was the upmarket, values-driven, supermarket Waitrose. Customers here had a clear preference for bottles.

Louisa Ziane, co-founder, performed a carbon impact assessment shortly after moving to selling beer in cans. “The cans were less than half of the carbon footprint of a bottle. And that then prompted a lot of internal conversations because Waitrose and Co-op, our biggest customers at that point, were both taking bottles.”

The company could change to cans more easily on its web shop. Here, they could try to push customers to switch to cans. The company tried using nudges, first through notifications at the online checkout, then by using pricing. This had some success, but more was had by providing a clearer environmental on can packs sold through the supermarkets.

Add it up

The sort of impact assessment—or carbon lifecycle analysis—Ziane performed is vital to understanding the emissions throughout a products life. “You look at the full value chain. You have the material itself, and that’s what’s called embodied emissions. Those are the emissions that are released in producing the empty bottle or can.

“Then you have the distribution phase, moving that empty packaging to the brewery, the moving the filled product to the customer.”

Ziane had previously worked for the Carbon Trust, performing this sort of analysis, so was able to create her own spreadsheet tool to track these emissions. Similar tools are available online, and will give a good enough approximation to guide a brewery’s choices.

Material conditions

The origins of materials have an impact here. Felix James, co-founder of Small Beer, previously worked for some of the world’s biggest brewing businesses and gained familiarity with how global supply chains work. He points out that while aluminium, as bauxite, and glass, as silica, are both abundant in the earth’s crust.

But while silica is found pretty much anywhere there’s sand, bauxite is only easily extracted in a few locations: specific regions of Australia, Guinea in west Africa, and in Brazil’s environmentally sensitive Amazon region.

A carbon assessment just assesses carbon. “If you compare a standard can to a standard bottle, the can wins out on carbon alone,” James says. But, he explains, this ignores other aspects of bauxite extraction, including labour conditions, habitat destruction, and the displacement of indigenous populations,

Check your weight, and your shape

As Ziane performed her analysis of Toast’s carbon impact, she could see clear evidence for the impact of package weight. “It’s the weight and shape, actually,” she explains. “We calculate emissions on a tonne-kilometre basis: the heavier it is to move, then the more emissions it’s responsible for in transportation. The glass is obviously much heavier, so that contributes to more emissions.”

Shape matters too though. As we saw in previous articles in this series, you can fit more cans on a pallet than bottles. “You can literally fit more liquid onto a lorry in cans, so you’re then making fewer journeys.”

Michael Comiskey, marketing manager at contract brewer Bevcraft agrees. “You will fit way more cans on a palette due to their size. They’re less bulky than a bottle, which needs to go into a crate or needs to be packaged a lot tighter.You will only fit a certain amount in bottles on the pallet as well, because the forklift won’t be able to lift it.”

It also means a drinker or a supermarket can keep more cans than bottles in fridges—cutting the impact of the energy used to keep beer cold.

Wraparound thinking

Consumers see only one or two levels of packaging: the can or bottle itself, and a collar or box used to hold beers in a multipack. But then more cardboard is used to box bottles and cans for distribution. “You have the cardboard box they’re packed into,” says Ziane. “We need bigger boxes for bottles, so therefore more cardboard to pack them.”

And even those boxes need to be stacked carefully on pallets, with plastic wrap often used, and subsequently disposed of—the light thin plastics used in pallet wrap are not easy to recycle efficiently, so may often end up in landfills or incinerators.

Felix James has seen alternatives to this deeply uncircular practice. “On the continent, they use velcro pallet wraps. You take the velcro off at the other end, and then it goes back.” For a medium or large brewer, regularly delivering lorry loads of beer, an extra carbon and materials saving could be found here.

End of life

To be useful, a carbon assessment must be cradle to grave—from the bauxite or silica, to the can or bottle in, hopefully, a recycling bin.

Darren Fenton is co-founder and COO at Bevcraft. “For me, a really key point of cans and aluminium packaging in general is its infinite recyclability. A can that’s on a shelf today can be taken, served to a customer, recycled, and be back on the shelf as a can within 60 days. without any really heavy processing required.”

While cans do require re-smelting, currently an energy intensive process using fossil fuels, Fenton says there’s none of the grinding or crushing needed for bottles, and the transport of the used packaging and of recycled materials itself takes less energy.