Does coffee really sober you up?

Only time can sober up a person…not black coffee, cold showers, exercise, or any other common “cures.” Alcohol leaves the body of virtually everyone at a constant rate of about .015 percent of blood alcohol content (BAC) per hour. Thus, a person with a BAC of .015 would be completely sober in an hour while a person with a BAC of ten times that (.15) would require 10 hours to become completely sober. This is true regardless of sex, age, weight, and similar factors.