Salting of fish tissue triggers a water movement to equilibrate the activity gradient. A mechanistic model that can predict the development of salt and water concentration as well as the water activity distributions, was validated by developing an experimental methodology that allows the access to the salt and water concentration distributions at any stage of the process. The model succeeded on offering reasonable predictions, with average RMSEs of 0.019 and 0.033 kg kg(-1) for the salt and water concentration distributions, and 0.022 for the water activity; as well as a mathematical framework that is independent of the salting conditions (e.g. brining, curing), which helps to understand why the system behaves the way it does. Additionally, it allows the establishment of a tool to have a better control of the salting time in order to ensure both organoleptic and safety requirements.