The production of bilimbi jam is an effort to diversify food and use local ingredients as a source of functional food. The purpose of this study was to determine the optimal formula for bilimbi jam based on consumer assessments through sensory testing for bilimbi jam. The treatment factors studied were variations in the amount of bilimbi fruit (X1) and sugar (X2). The treatment response observed was sensory analysis including colour, aroma, taste, and texture. The results of the RSM analysis show that the amount of bilimbi fruit and sugar has a significant effect on colour, and has no significant effect on the aroma, taste, and texture of bilimbi jam. The optimal formula was obtained at the amount of bilimbi fruit (X1) of 412 grams and sugar (X2) of 271 grams, with a target taste of 6 (like) and a colour target of 5 (somewhat like) and obtained a colour score (Y1) of 6 (like), aroma score (Y2) of 4.7 ≈ 5 (slightly like), taste score (Y3) of 5.6 ≈ 6 (like), and texture score (Y4) of 4.7 ≈ 5 (somewhat like). Bilimbi fruit can be used to make fruit jam with good sensory acceptability, so that it can be developed into a promising local food.