Mead is essentially just water mixed with honey that is left to ferment after adding yeast, resulting in what is also called ‘honey wine’, with an ethanol content of usually between 3.5% and 20%. Since soda is mostly water and comes with its own supply of sugar for yeast to feast on, this isn’t such a crazy choice in that respect. Just make sure to remove the carbonation, as the CO2 makes the soda too acidic for the yeast to be happy.
Instead of straight honey, caramelized honey was used for extra flavor after which the brew was left to ferment for a while. For extra flavor notes aged oak, vanilla and cinnamon were added as well, to ensure that the fermentation didn’t erase those core notes of the coke. The result was apparently rather flavorful, with about a 10.5% ethanol content, receiving the full approval of both tame test tasters.
You can get a cola cordial from a supermarket near me and I tried putting this in a few brews.
Once the sugar has gone it ends up tasting unpleasantly tart and chemically.
If I wanted to try this again I think I’d try getting the kola nuts directly and maybe adding the citrus flavour with peel instead of juice.