In daily life, people consume many liquids in their diet like water, soda, milk, juices, etc. Due to the growing demand of these liquids, many adulterants are being used in the market, which degrades the quality of the product and may be harmful to the human being’s health. For a human being, it is very difficult task to find out adulteration in the liquids that they are having in their daily diet. In order to resolve this problem, a device that is very easy to use and provides quick and accurate results is designed, where change in resonant frequency is the parameter used for adulteration detection. In this paper, a split ring resonator-based microwave sensor is proposed for the detection of adulteration in different fluids. The resonant frequency of the sensor is 9.24 GHz. The sensor design exhibit defected ground structure to obtain a sharp resonant frequency. The proposed sensor is fabricated and tested by using water and milk with adulteration (sugar, salt and soap). 2 µl drop of each fluid is placed on the sensor and a shift in resonant frequency from 9.24 to 7.3 GHz for water and 8.4 GHz for milk is noticed.