If you haven’t yet heard of the coke geyser you must have been living under a rock! Welcome to what is possibly the coolest, most fun (and messy) Christmas gift around and at a price that makes it a perfect stocking filler!
Firstly I’ll describe the coke geyser, then we’ll get to the real fun bit and I’ll show you a few videos.
The coke geyser is a small plastic tube with a pin in it that with attach to the top of a standard bottle of coke. What you do is put a few of the Mentos mints (provided in the pack) in the tube, attach it to the top of an open Diet Coke bottle (must be diet coke), then pull the pin and run.
As you pull the pin out, the mints drop into the coke, and what could be described as an explosion, eruption - or geyser - erupts out of the top.
Be careful where you play with this as the geyser goes high and you may well cause damage to grass and plants so best to play with this in a wide open space. Also, of course, this isn’t suitable for small children due to the literally “explosive nature” of it.
I’ve heard the reason this works is that the chemical reaction between the mentos and coke causes thousands of air bubbles to form rapidly in the Diet Coke bottle. As there isn’t enough space for all that air and coke together, it literally blows the coke out of the top.
OK, here are a few select videos specially for you to enjoy. Go on, I dare you to watch them and *then* tell me you don’t want one… 
