3D food printing allows the development of personalized food, but it is necessary to diversify the printable recipes to propose a varied food offer. The objective of this project was to explore the printability potential of different flours and to optimize a thermomechanical process (mixing and heating of water and flour) to ensure good print quality. A bibliographic study of 25 flours and an experimental screening of five flours was conducted. Thanks to the previous steps, soy and rye flour were selected because of their interesting nutritional value and their printability potential. An experimental design (10 trials) for each flour showed a significant impact of the process parameters studied (percentage of water content and duration of the thermomechanical treatment) on print quality. The reverse engineering approach demonstrated that the optimal water content is similar for both flour (Soy: 59%, Rye: 60%), but the optimal duration of the thermomechanical treatment is quite different (Soy: 27 min, Rye: 22 min).