As part of the LANDFEED project, partners in Spain are demonstrating how food waste from the hospitality and catering sector (HORECA) can be turned into a new source of bio-based fertiliser. This update looks at the progress of Use Case 1, from early lab-scale trials to the industrial demonstration now underway.
A circular economy solution for catering waste
AZTI leads Use Case 1 (UC1) in Spain, working with AUSOLAN, KOLLVIK-FR, FERTINAGRO, and NEIKER. The project aims to validate HORECA food waste as a feedstock for bio-based fertilisers (BBF). The process uses solid-state fermentation (SSF) with a selected fungal strain as the fermentation agent.
Compared with conventional fermentation technologies, the SSF process requires less water, generates minimal wastewater, and consumes less energy. By increasing nutrient density and bioavailability, the resulting fertiliser supports a more circular economy. It also reduces the carbon footprint of both waste management and fertiliser production.
Characterising the waste stream
The work began in 2025 with systematic sampling campaigns in representative institutional kitchens. The team then characterised these samples in detail, examining their physicochemical and microbiological properties to assess their suitability for fermentation. The analysis quantified dry matter, protein, fat, carbohydrates, and potential contaminants. It also identified waste generation patterns and seasonal variations across different kitchen typologies.
Managing highly variable feedstock
Food waste from catering services is highly heterogeneous, including plant-based leftovers, animal-derived residues, semi-liquid dishes, bakery waste, bones, shells, and occasional contaminants such as paper napkins. To address this variability, the team developed an integrated sorting and stabilisation approach. This ensures microbial safety, extends shelf life, and improves logistics, delivering a reliable, consistent feedstock supply for bioprocessing.
Ensuring traceable collection and logistics
Efficient collection and transportation logistics are critical for transforming food waste into bio-based fertilisers. The project identified source separation and full traceability as essential requirements. Consequently, the consortium has designed sampling, collection, transport, and storage procedures that comply with both Spanish food waste regulations and the EU Waste Framework Directive.
From pilot to industrial scale
AZTI initially optimised the SSF process at pilot scale at its own facilities, using approximately 30 kg batches of HORECA waste that AUSOLAN supplied and processing them in a small-scale drum reactor.
NEIKER assessed the fertilising potential of UC1 BBF in a greenhouse lettuce trial, comparing it against an unfertilised negative control (soil only) and a standard mineral fertiliser positive control that received the conventional fertilisation rate for lettuce cultivation. The BBF significantly outperformed the unfertilised control and produced root biomass comparable to the mineral fertiliser treatment.
Building on these results, the objective of UC1 is to replicate the process on an industrial scale. The consortium then carried out a first semi-industrial trial, using industrial processing equipment at KOLLVIK’s facilities between 22 and 30 June 2026. During the tests, the team successfully validated all process specifications using HORECA waste samples collected from local suppliers. This phase also let the team make final machinery adjustments and operational improvements before deployment.
Scaling up in September 2026
The consortium will run the industrial trial at FERTINAGRO’s facilities in Teruel, Spain, in September 2026. It will conduct a demonstration using several 300 kg batches of HORECA waste collected by AUSOLAN from their catering services. FERTINAGRO will then process and formulate the fermented material into a bio-based fertiliser. Two field trials on broccoli will subsequently evaluate UC1 as a biostimulant. The study will compare UC1 BBF with different fertilisation controls. It will assess soil nitrogen availability, microbial biodiversity, crop yield, and nitrogen uptake to determine the fertiliser’s agronomic and environmental benefits.
Looking ahead
Overall, the preliminary results demonstrate that solid-state fermentation is an effective route for nutrient recovery. It produces a protein-rich, mineral-enhanced fertiliser ingredient. By the end of the project, these outcomes should help strengthen Europe’s fertiliser value chain by delivering sustainable, cost-effective, and regulation-compliant bio-based fertilisers (BBFs). More broadly, the approach supports the transition towards climate-resilient agricultural systems and more efficient resource use.
