Food waste was mixed with vegetal bulking agent. Chipped pruning residues of winter wood were provided by the garden service of the Pamplona City Council and were added as bulking agent (dry matter 55–60%) to favor aeration and prevent leachate formation. For all treatments the bulking agent was replaced, following the first addition of waste, by commercial compost without sifting to promote the activation of the composting process (5 kg/bin).