The stability of the sucrose molecule throughout processing is of the utmost importance, because in principle any sugar loss will increase the production costs per tonne of the obtained white sugar. Colour in processing is an important technological parameter too, since only an adequate colour control in processing allows the cost-effective production of white sugar crystals of the required quality. For process control of both sugar hydrolysis and colour formation it is necessary to understand the effect of pH value, temperature and retention time on these phenomena. This paper will describe the possible causes of sugar hydrolysis and colour, as well as how to control pH values and temperature in processing in order to limit the technological impact of both reactions in which invert sugar plays a central role.