This study determined some physicochemical and sensory properties of hazelnut butter fortified with grape molasses (GMHB), and stabilization conditions were determined for 37 days at 25 and 45 oC. The most suitable GMHB formulations in terms of structure, colour, viscosity, aroma, and preservation of stability were among 73-85.5% Hazelnut puree (HP), 14.5–25.5% Grape molasses (GM), 1.5-3% Stabilizer (Stb) and 1.5% Skim milk powder (SMP). The highest cumulative oil separation was observed in the control samples without Stb, stored at 45 oC. Also, mathematical equations reflecting the relationship between oil separation rates and storage processes (temperature-time) can be used to calculate cumulative oil separation (R2 = 96-99.8%). Added GM, in addition to the rich composition of HP, further enriched the GMHB in terms of mineral matter, sugar, and total phenolics. Among the GMHB formulations, the panellists most liked A3 with high average colour, taste, and odour scores.