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Coffee grounds – natural, compostiable and very valuable Food for the soil

Thirty tonnes of coffee are required every year by JURA’s machine testing lab in Niederbuchsiten. Obviously this generates a lot of used coffee grounds. They’re too good to throw in the bin, says JURA, so the grounds are given to a local farmer. He uses them on his fields as a natural fertilizer, returning to nature that which was previously harvested elsewhere.

Thirty tonnes of coffee a year. If you try to picture that your imagination will quickly be overloaded. Thirty tonnes is about the weight of sixty cows. Or thirty small cars. It’s a lot. This amount of coffee is required every year for testing machines at JURA. In the test lab, bean-to-cup machines run constantly, puffing, flushing and grinding without pause. Carefully lined up in rows, automatic machines of all sorts undergo rigorous testing, from the smallest single-cup machine for home use to the biggest professional machines which will go on to provide entire offices with their daily energy boost.


Large pipes feed the coffee beans continuously into the hoppers of the automatic machines so that the coffee production process never has to stop. Every new development has to undergo intense fatigue tests here before it is ready for the market. Fatigue tests involve the machines being in constant operation for twenty-four hours a day from Monday morning until Saturday evening. Tests are conducted on six days a week in this way. All results are recorded in precise detail – automatically, of course. Each machine is connected up to a large number of cables which relay all the information directly to the test log. An automatic machine will spend several months here on the test bench. Not only new products need to prove their quality in the fatigue tests, however: new components for automatic machines already on the market are also tested prior to introduction.


The coffee grounds which accumulate in the laboratory are collected in large boxes. These can quickly fill a whole container. Around every two weeks, a van comes to take the grounds from JURA to the green waste recycling unit at the nearby Stall Studer in Kappel. A local site was deliberately chosen to process the grounds in order to avoid long transport routes. 

From laboratory to field

The processed material is reused in the agricultural sector as a nutrient-rich compost. On arrival at Stall Studer, the container is emptied at a large collection point. A sizeable load of green waste is already waiting there, as the grounds are first mixed with other materials before being piled up at the side of the field for composting. ‘As a chaff cutting and green waste recycling service we are supplied with a variety of materials. We process these and mix them with the coffee grounds,’ explains Fabian Studer. The compost then spends eight to twelve weeks at the side of the field. During this period, it has to be turned on a regular basis. This allows enough oxygen to get in to cause the material to compost down. It also ensures that the hygienization process is completed.

It’s a steamy affair when Fabian Studer gets to work with the compost turner. The compost can heat up to a temperature of 70 degrees inside. Together with oxygen, water is an important element in the composting process. The compost must be neither too wet nor too dry, so it may have to be covered in fleece, depending on the weather.

When the compost is ready, it is spread on the fields, where it works not as a traditional fertilizer but as a soil conditioner – as Fabian Studer explains: ‘We use the coffee ground compost as a natural fertilizer on our fields. The fertilizer is not intended to promote growth but to feed valuable nutrients back into the soil. The compost also enhances the formation of humus. In this way, we can guarantee a sustainably fertile soil which is efficient over the long term. In Switzerland in particular, where space is limited and the land is intensively farmed, it’s very important to manage the soil sustainably.


All you need to know about compost and how it works

The most important factor in producing the compost is to get the mix right. This varies greatly depending on the time of year. ‘We are supplied with a variety of materials: green waste as well as compostable kitchen and garden waste. In the summer, there’s obviously a lot of grass – that makes the mix a bit ‘fat’, or nutrient-rich. In the winter, it consists mainly of woody material and leaves, in which case the coffee grounds are a particularly valuable addition, because they supply nutrients and energy.’ The compost does more than ensure good plant growth, it also promotes the diversity of organisms in the soil. Among the countless numbers of these is the earthworm. The earthworm is the farmer’s best friend, and for good reason: it improves soil quality both with its nutrient-rich excretions and its general activity, which loosens the soil structure. Even the smallest organisms, visible only through a microscope, benefit from the coffee ground compost. 

Soil that contains lots of different creatures and microorganisms is also more conducive to healthy plant growth so Fabian Studer is more than happy to apply the compost to his fields. His wheat crop benefits from it, and is processed into IP-Suisse bread grain. And barley, silage maize and the oil seed rape that turns the countryside a dazzling yellow when it flowers in the spring all grow extremely well thanks to the soil conditioner. Extensive fields with closely packed rape-seed plants enhance the beauty of the landscape with their intense yellow blooms, and in this region rape seed is a very valuable crop in nutritional terms as it is an important food source for humans and animals. 

The soil at the farm in Kappel is has been benefiting from the nutrients in the coffee grounds for two generations, as the JURA laboratory has been supplying grounds to the Studer family for almost two decades now. It’s been a lasting partnership with many positive benefits for people, nature and the environment.


The Studer family favours regional products in its self-service café, the Hofkafi. Stephanie Studer, who runs it, regularly serves home-baked goods to the guests. A small farmer’s breakfast with plaited bread, jam and coffee or a cold drink is also recommended. If you would like to celebrate a special occasion in these lovely surroundings, you can hire the Hofkafi for your private party. 


Expert tip from Fabian Studer:

‘You can use coffee grounds in your own garden. You can start your own compost heap, adding organic kitchen waste, grass cuttings and hedge trimmings – and, of course, coffee grounds. If you grow flowers or vegetables in your garden your compost will supply them with valuable nutrients, and soil organisms will appreciate the improved structure of your soil. Also, children find it very interesting to see how compost is used in the garden. They love to get involved and they can learn a lot about nature and our food.’

 

Images: Derek Li Wan Po