Bread is a growing staple food in Indonesia. Many bread-like quality relies on its wheat flour. However, Indonesia heavily relies on imported wheat. Local legume jack bean (Canavalia ensiformis L.) can partially substitute wheat flour in bread. Heat Moisture Treatment (HMT) can also be used to improve bread quality. The effect of HMT temperature (90°C, 85°C, 80°C, and 75°C), time (3, 6, and 9 hours) and adjusted moisture content (30% and 27%) on swelling power, solubility, and lightness of jack bean flour was explored. There was no significant effect of HMT on swelling power, solubility, and lightness of jack bean flour. HMT also generally decreased the swelling power, lightness, and solubility of jack bean flour. The selected HMT treatment was based on the average swelling power of each temperature, time, and adjusted moisture. The HMT treatment of 80°C , 9 hours, and adjusted moisture of 30% was selected. After further analysis, the selected treatment had a significant effect on moisture, protein, ash, and carbohydrate content. The selected jack bean flour had increased moisture (8.93±0.39%), ash (3.29±0.02%), protein (34.95±0.27%), and decreased carbohydrate (48.83±0.49%) compared to control jack bean flour (5.83±0.18%, 3.51±0.03%, 33.47±0.35%, and 53.02±0.60% respectively). The selected treated flour was incorporated in liquid fermented pan bread at different ratios of wheat flour to jack bean flour, including 100:0, 95:5, 90:10, 85:15, 80:20, 75:25, and 70:30. The effect of ratio to weight, volume, crust and crumb lightness, hardness, and sensory evaluation was explored. The ratio of wheat flour to modified jack bean flour had significant effects, such as increased hardness and decreased crust lightness, volume, scoring values and hedonic values. Liquid-fermented pan bread made with 90:10 ratio was the selected formulation based on comparable hardness (960.91±301.84 g), volume (579.17±7.36 cc), and sensory results to control pan bread (782.50±23.18 g and 503.20±38.85 cc, respectively). Therefore, partial substitution of liquid-fermented pan bread with up to 10% HMT modified jack bean flour is acceptable as a wheat flour substitute for liquid-fermented pan bread.