Your blood alcohol concentration (BAC) does not decline very quickly. It can differ a bit from one person to the next, depending on things like body composition. But reports generally find that it will go down by 0.015% every hour after it peaks.
The peak does not necessarily happen right away. When someone has a final drink, it takes time for alcohol to move through their system. The peak could come significantly after they physically consume the drink, and then the body begins trying to metabolize that alcohol and get it out of the bloodstream. This is when their BAC starts going down by the aforementioned 0.015% per hour.
Not waiting long enough
Misunderstandings about BAC rates sometimes lead to DUI charges.
For instance, say that a college student goes to an IU football game with their friends, where they have a number of drinks. They wait for an hour before driving, knowing that they need to sober up. But if they had a high BAC level, they are not going to be anywhere close to zero after just one hour.
Additionally, there is nothing a person can really do to cause their BAC to go down faster. Things like drinking a cup of coffee, often touted as a cure for inebriation, actually just wake a person up as they consume caffeine. But the person will still have an elevated BAC level.
DUI defense options
If you are facing DUI charges in Indiana, they can lead to fines, jail time, license suspension and more. Be sure you understand all of your legal defense options.