Accurate dielectric characterization of liquid materials is critical for a wide range of applications. In this paper, a permittivity measurement method featuring a planar immersible probe consisting of a small loop loaded with a spiral resonator is presented. The design of the probe is described herein, and its performance is demonstrated through measurements and benchmarking with a widely accepted commercial dielectric measurement solution. It is shown that the probe renders accurate permittivity values for various edible oils, crude oil and ethanol solutions with varying concentrations.