If you purchase once you are through security they box it and then you can carry it on the plane but if you buy before security you have to either check it or pack it in your suitcase and check it.
Sounds easy! Last year I thought I heard someone being told that they would still have to check the alcohol, even buying it after we had gone through security, but it sounds like that is not the case. Thanks!
I bought my 6 bottles before checking in they packed them great they were check thru to home. After I got into the airport I had time to kill so I went to check out prices there they were they same. A employee ask if I needed help I told I had already purchased my booze so I couldn't buy anymore she informed me that I was through security and I could so I picked up another 6 to carry on
One thing on the carrying on, it counts torwards your carry on limit. Seems obvious now, but we are wishing we had checked one of our carry on bags this morning.