Method of continuously manufacturing an alkenyl succinic anhydride emulsion, hereinafter referred to as ASA, in an aqueous solution of cationic starchy material implemented by means of an emulsification unit comprising an emulsification chamber receiving a couple rotor /stator, with the method comprising the steps of: - a) providing an aqueous solution of cationic starchy material of which the dry matter content is between 7% and 12% of its total weight, - b) conducting separately the ASA and the starchy material aqueous solution from step a) and feeding the emulsifying chamber with ASA and with the starchy material in the aqueous solution from step a), respectively thanks to two separate fluid inlets (E1, E2), in such a way as to not mix them before they are introduced into the emulsification chamber, - c) mixing the ASA and the aqueous solution of cationic starchy material from step a), in the emulsification chamber, in such a way as to obtain a cationic starchy material/ASA dry matter weight ratio less than 1, - d) carrying out in a single pass in the emulsification unit an emulsion from the mixture of step c), and this, without a recirculation loop, - e) diluting the emulsion from step d), in the immediate vicinity of the outlet (So) of the emulsification unit, having an axis tangential to the periphery of the rotor, with the diameter of the outlet (So) of the emulsification chamber being between 3 mm and 10 mm, with the step of diluting being carried out downstream of the outlet of the emulsification unit, by conveying the undiluted emulsion according to a straight trajectory, from the outlet (So) of the emulsification unit, and to the location of the dilution, without a change in direction, by means of a dilution device comprising a straight section of pipe of which the proximal end is connected to the outlet (So) of the emulsification unit and of which the distal end opens into a bend of a pipe with a larger diameter and which channels the dilution liquid, and wherein the dilution factor of the step e) is between 4 and 21 in such a way as to obtain a minimum speed of the fluid in a pipe downstream of the dilution device, greater than 0.2 m/s. - a) providing an aqueous solution of cationic starchy material of which the dry matter content is between 7% and 12% of its total weight, - b) conducting separately the ASA and the starchy material aqueous solution from step a) and feeding the emulsifying chamber with ASA and with the starchy material in the aqueous solution from step a), respectively thanks to two separate fluid inlets (E1, E2), in such a way as to not mix them before they are introduced into the emulsification chamber, - c) mixing the ASA and the aqueous solution of cationic starchy material from step a), in the emulsification chamber, in such a way as to obtain a cationic starchy material/ASA dry matter weight ratio less than 1, - d) carrying out in a single pass in the emulsification unit an emulsion from the mixture of step c), and this, without a recirculation loop, - e) diluting the emulsion from step d), in the immediate vicinity of the outlet (So) of the emulsification unit, having an axis tangential to the periphery of the rotor, with the diameter of the outlet (So) of the emulsification chamber being between 3 mm and 10 mm, with the step of diluting being carried out downstream of the outlet of the emulsification unit, by conveying the undiluted emulsion according to a straight trajectory, from the outlet (So) of the emulsification unit, and to the location of the dilution, without a change in direction, by means of a dilution device comprising a straight section of pipe of which the proximal end is connected to the outlet (So) of the emulsification unit and of which the distal end opens into a bend of a pipe with a larger diameter and which channels the dilution liquid,