Alcoholism or Alcohol Use Disorder (AUD) is a significant global problem which negatively impacts all aspects of our lives. There are several alcohol testing and measurement tools availmarket that use a variety of bodily fluids including blood, plasma, breath, and sweat. However, the lack of passive and continuous sensing mechanisms, the cost and size of a dedicated alcohol sensor, and the social stigma associated with having a dedicated alcohol sensor has prevented the widespread adoption of the existing alcohol measurement tools. In this work, we develop a wristband augmented with low-cost backscattered infrared reflectance measurement capabilities for unobtrusive, passive and continuous ethanol alcohol sensing. Through measuring backscattered infrared light, we can detect rich information on the chemicals in and under our skin. This is due to the interaction between light and the various chemicals in and around the tissue. We demonstrate the efficacy of our proposed wearable system through a controlled lab experiment using human serum to create a skin phantom and with a user study (N=12).