Published by Bryan at June 6, 2011 The time to reduce 4 beers to 2 is two hours. The time to go from 2 beers to 1 is one hour, and the time to go from 1 beer to the legal limit is 30 minutes. It therefore takes a whooping 3.5 hours to reach the legal limit: 4 beers take seven times longer to metabolize than 1 beer.