St Arnold's root beer in the airport?

I'm flying in to the States for the first time in a decade very soon and I have specifically planned my flights to have a layover in Houston so I can get Whataburger. (Yes, I paid extra to fly via Houston. My priorities are in perfect order, thank you.)

Because Australia doesn't believe in root beer, I also want to have a good one before I leave the US again. Is there anywhere in IAH that I can get a St Arnold's root beer? My layover is unfortunately not long enough for me to be comfy with leaving the airport premises to acquire one, but I've got five hours so I should be able to enjoy one outside security if that's the only place I can get one.

..... if there's nowhere I can get one in the airport, is anyone willing to bribe security to smuggle a bottle in for me?