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Our addiction to single shot coffee capsules is not good for the environment, because of the energy to grow the beans, make the capsules, brew the coffee, and dispose of the waste. But there’s an upside: capsules turn out to be a more sustainable way of drinking espresso than nearly any other method of making coffee. And according to new research, recyclable aluminium pods are more environmentally friendly than all other capsules, whether they are made from plastic or compostable materials.

These capsules, whether from Nespresso, Lavazza, Illy, Bosch Tassimo, Keurig, Nestle or a bevy of smaller companies, have quickly conquered the world; even connoisseurs and many Michelin-starred restaurants have opted for them.


In the US alone, sales of coffee pod machines have soared during the past decade, from 1.8 million units in 2008 to 20.7 million in 2018, according to market research firm Euromonitor. By now, more than 40 per cent of US households own an espresso pod machine; in the UK, it’s nearly one third. Green campaigners, however, have been critical of the rapid adoption of the coffee capsule, criticising the deluge of waste streaming from the pod-powered coffee makers. According to research by Halo, a British producer of compostable coffee capsules, every minute about 39,000 of these pods are made worldwide, while up to 29,000 are dumped in landfill sites.

It looks bad for the environment, but that’s not the whole story. To understand the environmental impact of feeding our coffee habit, it’s important to life-cycle assessment studies for the full range of coffee-making methods. Alf Hill, professor of chemical engineering at the University of Bath, looked at all the stages of coffee production, from growing the beans to disposal of waste, assessing the impact on ecosystems, climate change, and water.

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His team found that instant coffee comes out best, but that capsules are the runner up in the environmental impact stakes. Filter or drip coffee comes third, while traditional espresso has the worst environmental impact. “The impact, such as greenhouse gas emissions, water and fertiliser use, mostly occurs where the coffee is grown,” says Hill. “Capsules tend to need less coffee input to make a single drink and so their overall impact can be lower even though we see more waste when we throw them away.”

Maxwell Colonna-Dashwood, a barista and co-owner of Bath-based specialty coffee shop Colonna & Small’s, who collaborates with researchers, says that “instant coffee extracts a lot from the bean, so uses less coffee per cup,” although he adds that it’s not necessarily performing well on other aspects of sustainability.


Hill's research backs up other studies conducted during the past few years, which suggest that capsules are environmentally less harmful than alternative coffee-brewing methods. Aside from the environmental impact of growing beans in the first place, the second biggest hit is the energy it takes to brew coffee. That’s why barista-made espresso fares so badly in terms of its environmental footprint: a lot of energy is needed to brew just a tiny single espresso cup. Capsules, on the other hand, are more efficient. The coffee machines only flash-heat the amount of water needed for one portion, unlike, for example, boiling a kettle.

Sebastien Humbert, an expert in life-cycle assessment studies at Quantis, a company that works with many organisations to improve their sustainability, cautions that if you take a responsible consumer — not an average consumer — then it is possible to make drip-filter coffee with less negative impact than capsules, albeit just ever so slightly. “However, if you are an irresponsible consumer, if your drip filter machine is very inefficient, if you leave it on, if you make more coffee than necessary, then you can make drip-filter coffee significantly worse than capsules,” he says.

Colonna-Dashwood says that despite the many studies showing that drip coffee and espressos are actually worse for the environment than capsules, the broader public simply doesn’t take any notice. People are just focussing on how capsules are killing the planet. “So a lot of work is going into making capsules more sustainable — because there is a sales opportunity in making them more sustainable, as people think they are bad — and not because that's actually a really unsustainable way of drinking coffee. It’s all very ironic,” he says.

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A study by Quantis compared the electricity consumption during brewing, heating and wasting coffee for single-serve and drip coffee preparation. It found that single-serve coffee uses an exact serving of fresh coffee, which cuts coffee waste, while people making drip coffee often have leftover that they throw away. And espresso makers that sit on a gas hob or a hot plate use significantly more energy than a capsule machine does.


Research by KTH in Stockholm, meanwhile, found that filter coffee has the worst environmental impact, because cup for cup, filter coffee uses more beans to prepare a single cup — about seven grams, compared to 5.7 grams for capsule coffee. Add that up to billions of cups of coffee drunk around the world each year and it quickly creates huge increase of the amount of coffee beans that have to be grown, harvested, processed and transported, plus all the energy needed to heat the water when making the cup.

As Colonna-Dashwood’s coffee shop is not far from the university in Bath, many students and professors regularly wander in, and occasionally he chats to them about coffee and the science behind it. That’s what happened in 2012, when he made a latte for Chris Hendon, a chemistry PhD student. They started chatting about how the composition of water affects the taste of coffee; the discussion led he pair to first co-author a paper in the Journal of Agricultural Food Chemistry and later a book, Water for Coffee.

Last year, Colonna-Dashwood decided to talk to Bath scientists again. He approached Hill at the chemical engineering department and asked him to find out which capsules are actually best: aluminium, plastic or compostable. The result, says Colonna-Dashwood, is that aluminium capsules.

The bulk of capsules on the market, however, are plastic, most manufactured by Lavazza, Nestle, Illy, Nescafé Dolce Gusto, L'Or Tassimo and K-Cup Keurig. Some plastic capsules, such as mixed plastic ones by Nestle's Nescafé Dolce Gusto, are recyclable. L'Or Tassimo plastic capsules are recyclable, but have to be dropped off at some 180 public drop-off locations around the UK. K-Cups in the US have aluminium tops and are partly recyclable: that is, once you take it apart, you can recycle the aluminium. In Canada, though, K-Cup pods are recyclable as of the end of last year, and the company plans to be making all its pods from polypropylene number five plastic, a widely accepted recyclable material, by the end of 2020, says Keurig spokesperson Katie Gilroy.

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Since 2010, Nespresso has been making its own fully-recyclable aluminium capsules, but just like with L'Or plastic capsules, there’s a catch: people have to return them to Nespresso to be processed at the company's own recycling factory. That’s because Nespresso capsules are not pure aluminium, which is widely recycled — they have silicon lining, so the capsules need a bespoke recycling process. Still, trying to motivate consumers to be greener, the company even provides free return bags for the capsules you might buy. Alternatively, it's possible to drop off used capsules at a Nespresso boutique, at one of over 7,500 collection points including CollectPlus and Doddle locations, says Crosskey, or request a collection from your home. At the moment, the recycling rate is 25 per cent.

In 2017, Nespresso ran a six-month pilot recycling project with the London borough of Kensington and Chelsea. The company gave 190,000 residents special purple bags to collect their used Nespresso capsules for pick-up during the council’s regular recycling rounds. Similarly, in March 2019, the company started working with the New York City Department of Sanitation and Sims Municipal Recycling to improve recycling rates.

Colonna-Dashwood says that while Nespresso’s recycling factory is top-notch, the hassle and burden placed on customers means that adoption rates are not as high as they could be. But even with his company's own aluminium capsules that can be thrown into your regular household recycling bin, coffee from each capsule has to be emptied first. Realistically, probably not many coffee drinkers would be willing to do that on a regular basis, says Piotr Barczak, senior policy officer for waste with the European Environmental Bureau, a network of more than 143 environmental citizens’ organisations. So consumer behaviour plays a role, he says.

“Coffee capsule companies claim their products are recyclable, and they are right. The problem is that they are not well collected, and their recycling is complicated,” Barczak says, so many coffee drinker don't bother. A refundable deposit fee might incentivise more people to return the capsules, but that’s not currently built into the business model of Nespresso or its competitors.

Still, Colonna-Dashwood thinks that if Nespresso and other companies were all to switch to recyclable aluminium capsules, it may be easier to convince consumers to chuck the waste coffee into the home compost bin and throw the capsule into the recycling one. And that, according to his and Hill's research, would be the best option in terms of the environmental footprint — always with the exception of instant coffee, which fares best in all life-cycle assessment studies.

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It's unlikely, though, that Nespresso decides to remove silicon in its capsules. For the company, bespoke recycling comes down to intellectual property: the capsules containing silicon are patented, which originally was used to prevent rivals from making pods that work in Nespresso machines, although a lawsuit put an end to this approach. “So if they copied us and got rid of their silicon lining, they’d lose what they see as a competitive advantage. So they're sticking to their IP,” says Colonna-Dashwood. And, he adds, even post-lawsuit, the Nespresso machines are made in such a way that Nespresso capsules fit best.

Humbert agrees that if aluminium capsules are fully and widely recyclable, they would indeed be better for the environment than plastic ones (even if plastic ones are also widely recycled). Having said that, the most recent Quantis research suggests that producing plastic pods uses less energy than making aluminium ones, so unless the latter are more widely recycled, then plastic capsules might come out better after all.

Recent studies have shown that plastic bags that claimed to be biodegradable were able to hold shopping three years after staying in the ground or in the ocean – and plastic pods have at least as long a lifespan.

So what about compostable capsules? Both Colonna-Dashwood and Humbert agree that they are not great – because they are rarely disposed of correctly. If you throw a compostable capsule into a municipal incineration plant, there is no benefit to it being compostable. “People often think that compost is by definition better but it's not necessarily the case,” says Humbert. Producing the compostable capsule pollutes as much or even more than producing a plastic one. And if it ends up in a landfill, it will degrade — producing methane that will end up in the atmosphere. “In a landfill, you want things to stay, you want it to be stable. And if you put the capsule into your backyard, our experience shows that the backyard compost is not good enough to actually degrade it, that it will take years,” says Humbert.

However, if compostable capsules are not thrown away in regular trash but put into special bins that are taken to compost or, even better, to biomethanisation facilities, then they are better than aluminium or plastic ones (even if both of these are widely recycled), says Humbert. The problem is, currently it's rarely the case.

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Still, companies are experimenting with compostable materials, and Lavazza, for instance, recently launched its own compostable capsule, called Ricco. Colonna-Dashwood is looking into compostable capsules as well. “People will continue to work on compostable capsules, and if somebody comes out with some new biopolimer, I'm very open-minded to that,” he says. London-based Sendero Specialty Coffee has made compostable capsules from biopolymers such as starch, glucose and lignin, which is found in wood bark. “The capsules decompose within six months, and can be thrown away the same way food waste is thrown away,” says co-founder Hutan Farbood.

There are other solutions, too. Seattle-based startup Atomo recently launched “molecular coffee”, which does away with real coffee beans altogether. It’s based on scientifically engineered molecular compounds that are still supposed to give you your early morning caffeine kick. “We looked at all the compounds in coffee at a molecular level – the body, mouthfeel, aroma, colour – over 1,000 compounds in a roasted bean,” the company says. To design the aroma and flavour, Atomo uses naturally-derived compounds, while skipping “the polysaccharides, oils and proteins found in the insoluble part of the coffee ground”, according to Jarret Stopforth, Atomo’s chief scientist. He says that the “sustainable and upcycled plant-based materials” in Atomo’s product “deliver the same great effect”.

Atomo’s research might come in especially handy in the future, as more and more studies now warn that climate change is making it harder for coffee plants to survive and thrive. Up to 60 per cent of what coffee drinkers consume comes from the Arabica strain, and Arabica is very sensitive to temperature increases, which affects plant physiology. As lower-laying areas become warmer, Arabica stops growing. A recent Nature paper warns that in Ethiopia, where Arabica is mainly grown, 60 per cent of coffee agriculture won't be possible by 2100. Researchers in Costa Rica, meanwhile, have created genetically-modified hybrid coffee plants that seem to be more resistant to extreme weather changes.

Of course, capsules being better than most other coffee-making methods doesn’t take away the fundamental fact that any product that generates waste poses an environmental problem. It’s just a question which lesser caffeinated evil we choose.

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