Tampere grinder pilot wins users but fails to improve sorting

A food waste grinder system tested in Tampere has been technically successful and received positive feedback from residents, but it has not improved the sorting of food waste, Yle reports.

The system has been installed in a student housing building in Tampere’s Kissanmaa district. Food waste is collected through grinders fitted into the kitchen sinks of each apartment.

Residents flush food scraps and other biodegradable waste into the grinder with cold water. The machine turns the waste into a finely ground slurry, which flows into an underground collection tank.

Most of the liquid is separated and sent to a wastewater treatment plant. The remaining food waste is emptied from the tank by a vacuum truck.

Resident Mikael Rauste said the system had made waste sorting easier by eliminating leaking and unpleasant-smelling food waste bags.

Similar food waste grinders are used, for example, in the United States, but a comparable waste management system is not known to be in use elsewhere as a whole.

The system was developed by Tampere-based company Ber. Chief executive Joonas Salonen said the idea originated at his family’s holiday cottage, where food waste was sent through a grinder into a sealed tank in the same way as toilet waste.

The system initially required residents to learn how to use it. Large pineapple leaves and popcorn kernels, for example, should not be put into the grinder because they do not break down. Rauste said the grinder once became jammed after too much waste was added at once and had to be opened by a maintenance worker.

The pilot was carried out in a building completed at the beginning of 2025. Pirkan opiskelija-asunnot, or POAS, said the system had worked reliably, had required practically no maintenance and had received mainly positive feedback from residents.

Early results suggested that the sorting of food waste had improved. By the end of the pilot, however, more food waste was found among mixed waste than the average for the area’s conventional waste management system.

The pilot was too short to support permanent conclusions about the system’s effect on sorting. Wider use also requires approval from the authorities.

Tampere’s waste management board will examine the results next week and assess whether the system could be introduced more widely in the city. Waste regulations require the collection tank to be emptied at least once a month, although the system could allow longer emptying intervals.

POAS is already planning to install food waste grinders in a student housing building in Hervanta, but it must still consider whether to expand their use. The system would be easier to install in a new building, while existing buildings would require extensive pipe renovations.

POAS chief executive Timo Jokinen said the system would cost money that would ultimately be reflected in residents’ rents, and that not all buildings would necessarily be suitable for it.