A method for determining the bacterial charge in a liquid or semi-liquid product, including: preparing a quantity of liquid or semi-liquid product to be analyzed; keeping that quantity of liquid or semi-liquid product at a preset measuring temperature (Tm) and deriving values (α) representing an angle of electrical impedance of the liquid or semi-liquid product at predetermined time instants; deriving an indication of the presence of a bacterial charge in the liquid or semi-liquid product as a function of the time trend of the values (α) representing the angle of the electrical impedance.