Abstract Substantial improvements in the performance of amperometric biosensors for alcohols are achieved by subjecting the glassy carbon transducer to an electrochemical pretreatment prior to the immobilization of alcohol dehydrogenase. The enzymatically generated dihydronicotinamide adenine dinucleotide (NADH) can thus be detected at a substantially (∼340 mV) lower potential compared to the untreated surface. Hence, highly sensitive low‐potential amperometric sensing of alcohols is accomplished without the assistance of a surface‐bound electron mediator. Applicability to alcoholic beverages is illustrated.