Ceramic firing, by giving artefacts both their mechanical properties and part of the final aesthetic features, appears to be a critical stage in pottery production. Several stages of production can be restored from finished products or structures found in archaeological context, but firing can alter or delete clues about previous steps. The significance of the unfired sherds of the Mas de Moreno lies in the unusual and privileged access they provide to these early stages of ceramic production, in an Iberian workshop of the Late Iron Age.