Did you know that your morning cup of coffee contributes to six million tonnes of spent coffee grounds going to landfill every year? This does not have to be the fate of your caffeine addiction and there are many opportunities to up-cycle spent coffee grounds into valuable commodities.
From fresh fruit, to roasted bean, to used up grounds, coffee’s chemical composition offers a range of uses beyond making your daily brew.
Potential applications range from biofuels, to health products, and fertiliser for farms or your garden. So why are we throwing this precious product away?
The answer is that processing and production can be more complex than you might imagine – even when we’re talking about simply using coffee grounds in your garden. What’s more, many recycling initiatives to turn waste coffee into valuable commodities are still in their early stages.
You may have noticed that some cafes now offer free spent coffee grounds for customers to take home and use in the garden. In theory, this is a great initiative but the reality is that fresh coffee grounds are high in caffeine, chlorogenic acid and tannins that are beneficial to humans but toxic to plants.
The spent coffee must be detoxified by composting for a minimum of 98 days for plants to benefit from the potassium and nitrogen contained in the roasted beans. Without adequate composting, the benefits are scant (see below). So if you do take some coffee grounds home from your local cafe, make sure you compost them before sprinkling them on the veggie patch.
The good news is that properly composted coffee grounds offer a cheap alternative to agro-industrial fertilisers, potentially helping urban communities become greener and more sustainable. Savvy businesses have begun processing coffee grounds on a commercial scale, turning them into nutrient-rich fertilisers or soil conditioners in convenient pellets for use in the garden.
But why stop there? A potentially even more valuable ingredient is the chlorogenic acid. Although toxic to plants, as mentioned above, chlorogenic acid has potential as a natural health supplement for humans, because of its antioxidant, anticancer and neuroprotective properties.
The whole coffee production process is abundant in chlorogenic acid, particularly in raw coffee beans. Chlorogenic acid conversion efficiency is even better from green coffee pulp, with a 50% recovery rate, compared with 19% for spent coffee grounds.
As undersized and imperfect beans are discarded at this raw stage, many businesses have seized the opportunity to market green coffee extracts as a weight loss product, although more research is needed to confirm this potential.
The list doesn’t end there. Coffee waste can be used to create a diverse list of chemicals, including enzymes and hormones for digestion of common biological compounds and to improve plant growth; and feedstocks for high-end crops such as mushrooms. Coffee oil has even been trialled as a fuel for London buses.
With abundant waste supplies due to the popularity of coffee consumption, by recycling the byproducts, perhaps we can enjoy one of our favourite beverages without too much guilt.
Shopping can be confusing at the best of times, and trying to find environmentally friendly options makes it even more difficult. Welcome to the first instalment of our Sustainable Shopping series, in which we ask experts to provide easy, eco-friendly guides to purchases big and small.
The morning coffee ritual is serious business; Australians drink roughly 16.3 million coffees a day. Plenty of news coverage has been devoted to its health benefits and cultural significance, but how much do you know about the environmental cost of your daily latte?
Coffee is grown in some of the most biologically diverse regions of the world, sometimes causing significant damage. But there are choices you can make to reduce the ecological impact of your caffeine fix.
Coffee mostly affects tropical forests, as they are cleared to make way for coffee farms. But with certain cultivation practices, these coffee farms can support an impressive range of forest biodiversity.
The world’s most popular coffee type, Coffea arabica, grows under the rainforest canopies of Ethiopia. A natural requirement for shade means coffee is often cultivated under shading plants, from a single tree species to a diverse range of plant life.
However, to improve productivity, traditional coffee farms have been increasingly replaced with sun-tolerant coffee varieties that produce higher yields. Compared with shaded coffee, these simplified plantations support fewer native species, store less carbon, experience higher levels of erosion, and leach more nutrients. They also require more resources such as water and fertilisers.
The most important choice when it comes to sustainable coffee is the actual coffee and its cultivation. Cultivation can contribute as little as 1% or as much as 70% of the total environmental footprint of a cup of coffee. How the coffee is consumed (instant, fresh grounds or pods, for instance) has less influence.
The lowest-impact coffee is grown using traditional cultivation methods with minimal mechanisation. At the other extreme are large farms that are highly mechanised and require more fertiliser and pesticides.
A combination of traditional cultivation methods, maintaining shading plants, protecting local forests and buffering waterways (filtering farmland runoff with vegetation before it enters waterways), has the lowest environmental impact.
While searching for your daily dose of caffeine, you have probably come across several different sustainability certification logos. They are the easiest way to find out about how your coffee is cultivated, and have proved effective in protecting coffee landscapes from degradation.
The Rainforest Alliance requires a level of native vegetation to be maintained within each coffee farm. There is some criticism that the alliance has watered down its criteria in recent years, at least in terms of maintaining diverse shading vegetation. However, their certification leads to positive outcomes such as protection of waterways and native vegetation.
Australian Certified Organic is focused on protecting natural habitats and biodiversity, efficient water use, and minimising the use of chemicals in fertilisers and pest and disease management. These practices are strongly aligned with traditional coffee cultivation.
While certification programs are not perfect, logos can certainly act as a guide to sustainable products.
That said, products without logos aren’t necessarily unsustainable. Some small landholders with highly sustainable, shade-grown coffee can’t afford the expense of certification.
In this situation you can talk to your local roaster (or a distant one via the internet). Roasters may have direct relationships with their coffee growers and can tell you about their cultivation practices. Good questions to ask are whether the cooperative has any certification, whether the cultivation is organic or shade-grown, and whether the cooperative has any associated environmental programs.
Ultimately, a little knowledge of coffee cultivation and its impacts can go a long way in making wise and environmentally sound purchases. There is a huge range of coffee choices available, and good evidence that the choices you make can influence significant and positive environmental outcomes.