The Sprite Zero Experiment

For those who have seen the 'Mentos Experiment', this should be of interest to you. I bought two 500ml bottles of Sprite Zero from 7-11 a couple of days back. 2 for $2, cheap. Anyway, when I got home, I needed my caffeine fix and decided to add some concentrated instant coffee into the Sprite. Don't ask me why, it's just me, I have my moments or 'episodes' as some shrinks would call it. I took a teaspoon of instant nescafe, mixed it with a teaspoon of hot water in my jigger, poured the black stuff into the bottle and before I could say 'what the @$@$!', the Sprite erupted. It foamed and just kept flowing and flowing and flowing. Here's the interesting part. Mentos removes the fizz from whatever carbonated drink you put it into; coffee apparently doesn't. At this point in time, I don't know why; more testing is needed, but just for the record, I'm sipping what's left of my Sprite Zero as I'm blogging this - with fizz still inside. Any Einsteins out there?