Objective: To determine the shelf life of sausage under the natural and smoked processes to standardize their manufacturing process, evaluate their physicochemical and microbiological quality using a mathematical model of order zero chemical kinetics. Methodology: The sausage manufacturing process was standardized, and two cooking and preservation methods were applied: boiling and smoking in oak wood. For the shelf-life analysis, a partially staggered sampling was used. The product samples were kept refrigerated (2 to 6 °C, for 7 weeks), and physicochemical and microbiological analyses were carried out on them every week. A mathematical model based on order zero chemical kinetics was used with the obtained results to determine the shelf life of the processed products. Results: The shelf life of sausages depends on the applied preservation process; in the case of the traditional (hot water) process, the result was 33 d, and increased to 56 d in the smoked and cooked with dry heat, due to the water content of each product, as well as the smoking antimicrobial action.