A system for mixing solutions includes: a first container and at least one second container capable of containing solutions, each second container being capable of entirely containing the first container; means for displacing the first container and/or each second container capable of entirely immersing the first container in each second container; and rotational drive means for the first container so as to mix the solutions present in the first and second containers when the first container is entirely immersed in the solution present in the second container.