Drinking in the dark. A new method to distinguish use-alteration from natural alteration on Neolithic pots and evidence of acid liquid storage in karstic cave contexts

In the karstic regions of the South of France, caves were used as water source during the Late Neolithic. Different strategies of water collection were put in place, the most frequent being the positioning of very large ceramic containers under trickle points. Functional studies, and more specifically use-wear analysis, are seldom used approaches applied to ceramic assemblages and the identification of post-depositional processes remains a major challenge that affects interpretation, particularly in karstic contexts. In the case of Le Claux, this approach shed light on a possible storage of acid liquid, that was potentially fermented. This paper aims both to contribute to the discipline of use-wear studies applied to ceramic material by offering a new method to differentiate natural and man-made wears, and to offer a better understanding of cave activities in the Late Neolithic of the South of France. •The function of Neolithic cistern-caves is renewed by a use-alteration analysis on pots.•A new method to differentiate ceramic use-alteration from natural and post-depositional alterations is proposed.•Use-wear of ceramic vessels from a cave context may reveal the production of acid fermented liquids.