The purification of sugar beet distillery vinasse, a by-product of bioethanol manufacturing, was studied with a view to removing the insoluble compounds by precipitation in ethanol. Two influential operating parameters, i.e. temperature and ethanol:vinasse (w/w) ratio of the precipitation, were optimized by a simplex method. An optimum was reached for a weight ratio of 4.6 at 21 ◦C, that allowed 52.4% of the vinasse dry matter to be separated. Additional experiments were then carried out to establish a secondorder polynomial model from a Doehlert design and measure theweight of solid removed as a function of temperature and ethanol:vinasse (w/w) ratio used. In the experimental domain studied, results showed the veryweak positive influence of temperature and theweak negative influence of ethanol:vinasse (w/w) ratio onweight of precipitate obtained. In addition, the statistical model enables to determine the response surface in order to predict the variation in response when the values of variables are modified. Lastly, the sugar beet precipitation was successfully scaled up, enabling a mass balance of the process to be established. Results showed that a large proportion of proteins and pectins were separated during the process.