In the industry of panela (called uncentrifuged sugar by the FAO), is estimated that multiple-effect evaporators (EME), allow greater control and increases by 36 % the overall efficiency of process. However, the implementation of these technologies requires the technical adjustment of the process; it keeps the quality of panela obtained in open systems evaporation too. Condition has unveiled a technological gap with respect to influence of the complex reactions that occur during water evaporation and concentration of sugars on the characteristics of sugar cane and brown sugar. To fill part of this technological gap, the objective of the work presented here was determine the effect of the variables of evaporation, pressure and heat flux on the quality of sugar cane and the panela. To achieve this, it worked one experimental design, completely at randomized with 4x3 factorial arrangement, four repetitions and the variety of cane CC 85-46, without flocculant, adjuvant or antifoam. The results showed that heat flow densities of 17 kW/m2 and pressurized systems, adversely affect quality of panela in areas such as color, pH, glycoside and solidification rate, to the point of not meeting the requirements of resolution 779 of the Colombian Ministry of Social Protection from sucrose and reducing sugars.