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.