The aim of replicating a recipe in the laboratory is to reproduce the chemical reality that would have been observed by those who performed alchemical procedures, in order to better understand the relation between these and the way in which they are recorded in the written sources. The first step of replication is a philological assessment of the text with its problematic or even obscure aspects, taking into account all the cultural components that might have influenced its transmission and present form. The information derived from the text can then be used to discuss with the chemists the different technical questions raised by the procedure, in order to design an experiment that may shed light on what remains opaque in a purely textual dimension. For the chemists and historians of science, this approach may reveal much about material culture and technical knowledge. The philologist may use the results of a replication to, for instance, refine a translation, or to decide between variants that are on an equal footing from a purely textual point of view (especially in the context of a fluid tradition) and, in general, to understand more about the text, its formation, and the vicissitudes of its transmission.