A man in Hanoi inquired whether consuming lychee fruit could result in a positive reading on a breathalyzer. Concerns arise from the perception that lychee consumption causes a noticeable alcoholic odor on the breath. Experts confirm that naturally occurring sugars in lychee can ferment in the stomach, producing ethanol. This fermentation *can* lead to a detectable alcohol level, potentially causing a false positive on some breath alcohol tests, though levels are typically low. Individuals concerned about this possibility are advised to avoid consuming lychee immediately before alcohol testing or driving. The amount of fermentation varies based on individual metabolism and the quantity of fruit consumed.