Scientists developed a microwave microstrip line planar resonator sensor tool to detect water adulteration in honey. The tool is compact, cost-effective, and easily fabricated. The microstrip line resonator sensor is fabricated on a dielectric substrate, which is an insulator that can efficiently support electrostatic fields, such as ceramic or glass. The team tested honey samples with varying water content and found that the sensor’s resonance frequency consistently decreases with increased added water content.