A mixing device (5) for preparing aligot, comprising a mixing case (10) containing a chamber that opens at an inlet for conveying material to be mixed, and a mixing member, characterised in that said mixing member comprises at least one roller (11a, 11b) that is mounted rotating on a motorised shaft (12a, 12b), one or more bearing surfaces of the roller being designed to engage in a crushing manner with the surfaces of said chamber of the case (10).