Alcohol use especially high-risk drinking remains a serious public health concern. Recent calls for "precision intervention" require more in-depth understanding of drinking behavioral patterns for more individualized treatment. Currently, alcohol research has relied on self-reported questionnaire or biomarkers to measure alcohol use. However, self-reports are often subjected to social desirability bias or recall errors; whereas biomarkers are prone to measurement errors, confounders for false positives, and individual variations in alcohol metabolism. There is need for an objective, reliable, and nonintrusive way to measure alcohol use with high ecological validity.