Coca-Cola owns Barq's, and PepsiCo owns Mug, having acquired the brand in 1986. Unlike Barq's, Mug Root Beer is caffeine-free ...
For example, a 12-ounce serving of Coca-Cola contains 34 grams of caffeine, but the same serving of Barq's root beer -- one of the more popular brands that contain caffeine -- has only 22 grams.