Natural latex foam mattresses (NLFMs) are manufactured using the latex extracted in its purest form of milky white liquid, which is tapped from the trunks of mature rubber trees. The natural latex foam mattress manufacturing (NLFMM) process undergoes several processing stages before the natural latex is converted into an ultra cushioning material with a wide range of firmness and comfort. Among the other processing steps, the gelling process has been found to play a significant role in controlling the quality of the final product, provided that quality raw materials have been supplied to the manufacturing plant. This manuscript suggests a methodology for estimating optimal levels of parameters that affect the gelling process, focusing on minimizing the influence on mattresses’ surface quality deterioration. A case study has been performed in collaboration with one of the natural latex foam manufacturing plants to recognize main quality deterioration mechanisms and corresponding process parameters using the engineering robust design approach to establish the optimal combination of influencing factor levels.