This project aimed to create a standardized, ready-to-use Khao Soi sauce that maintains the authentic flavor of Northern Thailand while strengthening its market feasibility. Three formulations, including 2%, 4%, and 6% all-purpose flour, were created and evaluated. One hundred consumers participated in sensory evaluations, while physical properties, including water activity (aw), pH, color parameters (L*, a*, b*), and chemical composition, were also investigated. The 2% flour formulation got the maximum customer acceptance, with an overall like score of 4.52 out of 5, and received positive sensory evaluations for aroma, texture, flavor, color, and appearance. The results indicated an aw of 0.78 ± 0.10, pH of 6.58 ± 0.01, and color values of L* 44.48 ± 0.11, a* 5.19 ± 0.07, b* 16.57 ± 0.09. Chemical analysis found 74.74% moisture, 15.12% ash, 1.12% protein, 21.22% fat, 18.96% fiber, and 34% carbohydrate. The findings suggest that the 2% flour formulation provides an ideal balance of sensory attractiveness and quality, facilitating its commercialization and the broader distribution of authentic Khao Soi flavors, thereby contributing to the preservation of Lanna culinary culture.