Energy Drink

So, today my boss dude, Nathan, and I were checking wikipedia (an unreliable source) for information on what was in his energy drink. We found out that one of his favorites had Guarana in it, which is the main ingredient in



This stuff is the best drink in Brasil. It is kinda like Ginger Ale, but better. Anyway, the energy drink contains guarana, which has 3 times the amount of caffeine as coffee beans. I think I may need to switch from coffee to energy drinks. Why can't coffee contain guarana?