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) crosslinking 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.
