This research set out to compare the physical and microstructural characteristics of kefir made of milk, colostrum, and milk-colostrum mixes at various proportions. Kefir was made by adding kefir grains to 100% milk (P0), 80% milk + 20% colostrum (P1), 60% milk + 40% colostrum (P3), 40% milk + 60% colostrum (P4), 80% milk + 20% colostrum (P5), and 100% colostrum (P6). Fermentation was allowed under room temperature for 24 hours. The characteristics observed were color values, viscosity, pH, water holding capacity (WHC), syneresis, and microstructure. The result showed that the color of kefir (L* value, lightness); (b* value, yellow-blue), (a*, red-green), and whiteness index (WI) was significantly affected by raw materials. The viscosity of kefir was also affected by the raw materials (p