Abstract: A process for preparing a crosslinked gel of at least one polymer or one of its salts, including a) providing an aqueous medium containing at least one polymer, b) forming a homogenous gel from the medium from step a), c) bringing the gel obtained in step b) into contact with an effective amount of at least one crosslinking agent; d) crossliking the mixture formed in step c); and e) recovering the crosslinked hydrogel, wherein at least steps a) to d) are carried out within a hermetic cavity delimited at least partially by a deformable wall, the mixture present in the cavity being exposed, in step d), to conditions conducive to crosslinking.