Ore assaying techniques are here considered as a part of the silver production chaîne opératoire, in a mining industry context. Our aims are to understand the technique itself but also its role in mine exploitation. The experiments deal with small scale assaying techniques in use from the end of the Middle Ages and well described in 16th-century technical treatises. More than 50 assays have been made with argentiferous galenas. The precise operation studied is the smelting of the ore in a scorifer, in a mufe furnace, which produces a lead and silver regulus (which is then cupelled to obtain the silver content). It allows a reflection on the different steps of the assaying process (sampling, ore preparation, the addition of fluxes, etc) and the way it was considered and practiced in the past. This gives a concrete vision of the technique studied, essential in conjunction with the historical and archaeological approaches.