Although the recipe of original Coca Cola is secretly guarded by several of its company executives since 1886, it shows the following ingredients in its package: sugar or high fructose corn syrup, caramel color, coca extract, kola nut extract, lime extract, caffeine, phosphoric acid, vanilla and glycerin.
The basic “cola” taste from Coca-Cola mainly comes from cinnamon and vanilla.
For some interesting stories about coca cola formula, you can visit the following sites: