Abstract: A process and device for the crystallization of sugar syrup is described. Sugar syrup is cooked to provide a massecuite. Thereafter, the massecuite is subjected to at least one stage of continuous mixing under vacuum to promote crystallization of the massecuite. The crystallized massecuite is then separated to separate the crystals from the mother liquor. The mother liquor is thereafter divided into a first discharge which is water syrup poor and a second discharge which is water syrup rich. Substantially all of the first discharge is recycled to the continuous mixing stage under vacuum. Accordingly, the massecuite and the crystals are subjected to a treatment having continuity during mixing under vacuum to maintain homogeneity of the sugar crystals.