You can make your own white/clear Coca Cola too! I play with my food a lot and have experimented with this.
All you need is an old/used Brita filter and a beverage carbonator (or if you're like me, you have some sort of multigas siphon).
1. Pour Coke into Brita jug (with filter in place)
2. Retrieve colourless solution, and then recarbonate.
It tastes like Coke but is colourless. I had also messed with other variants that require fancier filtration (special carbon filters for example) and centrifuging, but the Brita filter has pretty good results.
Beverage companies make clear liquor by filtering their worst and cheapest beer through charcoal (a special carbon filter) to remove the color (the science of this is explained in sibling comments). Strong citrus flavors are then added to mask the original flavoring. Zima was a popular drink made in this fashion in the 1990s. A competitor to Zima, Smirnoff Ice, (which isn't vodka in the U.S) is still around.
That's really interesting. Does it taste bad? I can see why Smirnoff Ice has such a bad rep in the US (it's just a vodka premix in Australia - so it tastes like vodka and lemonade).
It depends on your tastes. It isn't high quality alcohol, but if you don't want the smell of alcohol in your breath, or want alcohol that tastes kind of like Sprite, then it's not bad.
When I tried it about a year ago, I had completely different results. I got something that looked exactly like Coca Cola without the carbon (so it didn't lose color), but it tasted very bitter and wasn't sweet at all (so it lost taste).
(Note: Coca Cola in here uses sugar, not high-fructose syrup like in US, so that might be it.)
OK, I learned this in A level (high school) chemistry, but I can't seem to find a wikipedia article about it.
They use clay beads, which are an aluminium mesh with H and OH groups weakly bonded to it (a weak ionic bond like this is called a "Ligand bond"[1]).
Firstly, it filters out bacteria and "bits" because of the porosity of the mesh (works like pushing current through a complicated network).
However, additionally it filters out non-H-or-OH ions from the water, which have a stronger Ligand bond with the Al mesh. (Obviously you eventually run out of H and OH ions in the network, as they're all replaced, which is when you need to change your filter.)
As such, we used clay-filtered tap water as 'distilled' water in all our experiments, because the worst it contains is bacteria and dissolved salts. I can't speak for the Coca Cola though, that's weird. I'm sure organic molecules would be small enough to get between the beads but too heavy/not ionic enough to bond to the mesh, or something.
It's chemically inert, but has a very fine porous structure (thus 'activated'), so it works as a mechanical filter that adsorbs anything large enough, like bacteria and even very large molecules.
Activated carbon, also known as activated charcoal, was the useful ingredient in "universal antidotes". Although the mixture (see link) is no longer used, activated charcoal still is.
Adsorption is due to weak bonds that form between molecules of a surface and a fluid. AFAIK this bond is not a 'new' chemical bond since it does not break / replace existing chemical bonds in both the adsorbed molecule and surface molecules.
Rather, in the case of carbon at least, the 'bonds' are the van der Waals forces.
All you need is an old/used Brita filter and a beverage carbonator (or if you're like me, you have some sort of multigas siphon).
1. Pour Coke into Brita jug (with filter in place) 2. Retrieve colourless solution, and then recarbonate.
It tastes like Coke but is colourless. I had also messed with other variants that require fancier filtration (special carbon filters for example) and centrifuging, but the Brita filter has pretty good results.