Recognizing Intoxication and Preventing Over-Service
Intoxication shows up in clusters of signs, not one at a time. Watch speech (slurring, rambling, volume changes), motor control (stumbling, fumbling money, spilling, swaying), coordination and balance, eyes (bloodshot, watery, unfocused), and behavior (loud, argumentative, overly friendly, drowsy, or emotionally volatile). Also track the pace and quantity of consumption and whether the guest has eaten.
Alcohol is absorbed faster on an empty stomach and eliminated slowly - roughly on the order of one standard drink per hour for many adults, and slower for many people. Standard drink equivalents matter: a 12-oz regular beer, a 5-oz glass of wine, and a 1.5-oz shot of distilled spirits are roughly comparable. A large cocktail or a high-ABV craft beer may count as two or more drinks. Time is the only thing that lowers blood alcohol; coffee, food, cold showers, and fresh air do not sober a person up.
Traps in questions: assuming a guest who is "just happy and loud" is fine; missing that a guest who has been drinking for hours may be impaired even if they seem composed; treating coffee as a remedy; and counting drinks without accounting for strength or size. Another trap is continuing service because the guest is a good tipper or a regular.
Worked example: a guest has had three 16-oz IPAs in 90 minutes, is talking louder than before, and knocked over a glass. The pace and volume exceed one standard drink per hour, and there are two behavioral signs. Rule of thumb: two or more intoxication signs plus a fast pace means stop alcohol service, offer water and food, and arrange a safe ride.