Delta airlines adheres to the Transportation Security Administration's guidelines concerning alcohol on planes. It is imperative that you know and follow these guidelines when thinking of taking alcohol with you on your flight. Failure to comply with these rules could prohibit you from boarding your plane or even cause you to be paced under arrest.
Alcohol that was purchased in the secured area of the terminal is allowed to be carried on the plane. There are certain guidelines that must be followed, however. You may have up to 5 L of alcohol that is up to 140 proof, and it must be in its original packaging. It may not be consumed onboard the plane.
Alcohol you purchase before you go through the security checkpoint must be put in your checked luggage. You may check up to 5 L of alcohol that is between 48 and 140 proof in your bags so long as it is sealed and will not break. You may check any amount of alcohol that you wish, as long as it is below 48 proof. Alcohol over 140 proof is prohibited.
Consumption On and Before Flights
You must be at least 21 years old to consume alcohol on Delta flights regardless of where you are in the world. Whether you will be served is at the discretion of the flight attendants, who will not serve someone who is visibly drunk. Per the Transportation Security Administration's guidelines, Delta airlines' flight attendants will not allow a passenger who they believe is intoxicated to board.