Impact of mesophilic co-composting conditions on the quality of substrates produced from winery waste activated sludge and grape stalks: Lab-scale and pilot-scale studies.

•Co-composting of grape stalks and winery waste activated sludge was studied.•The mesophilic microorganisms present in the WWAS suppressed the thermophilic stage.•Volume reduction in lab-scale was higher (60%) than pilot-scale (20%).•The fresh mix and the substrate composted outdoors proved useful for horticulture.