The research aims to determine the best blimbi juice (Averrhoa bilimbi L.) concentration as mayonnaise acidifier based on the emulsion stability, droplet of emulsion and color. The material used in making the mayonnaise were consisted of egg yolk, soybean oil, blimbi juice, salt, sugar, pepper and mustard. An experimental laboratory was conducted for this research by using Completely Randomized Design (CRD) with 5 treatments and 3 replications. The treatments were consisted of P 0 as control (0% blimbi juice), P 1 (5% blimbi juice), P 2 (10% blimbi juice), P 3 (15% blimbi juice), and P 4 (20% blimbi juice). The obtained data were then analyzed by analysis of variance (ANOVA), and followed by Duncan Multiple Range Test (DMRT) to determine any differences. The results showed that blimbi juice gave a highly significant difference (P<0.01) on the emulsion stability, droplet of emulsion and color of the mayonnaise. The average emulsion stabilities on P0,