The food sterilization process with the gamma irradiation technique is highly determined by the accuracy of the absorbed dose. One of the absorbed dose measurement systems that can be used to monitor food irradiation processes is radiochromic dosimeter. So, the application of radiochromic dosimeter in the food irradiation is very necessary. This paper reports a simple dosimetry system using liquid radiochromic. The liquid dosimeter dye was prepared from Hibiscus sabdariffa L. (Roselle) dried flower extract using the maceration method in ethanol solution. The dosimeter was tested using gamma ray from a Cobalt-60 source at the medium dose level from 1 to 10 kGy. The color of the dye fades from red to clear gradually with an increasing dose of gamma irradiation. UV-visible characterization shows that the dye solution has an absorption peak at 530 nm. This peak absorption value decreases as the dose of irradiation increases. The stability of unirradiated and irradiated liquid radiochromic dosimeters has been observed for 30 days and shows good stability. These results indicate that liquid radiochromic can be applied as a routine dosimeter for the treatment of food irradiation at the medium dose level.