Last Christmas, I was given a home cola-making kit. It’s a pretty simple setup - mix warm water, yeast, sugar, and flavor extract, bottle, and let sit a few days to carbonate. I made up two 2-liter bottles of it, drank one and found it tasted too much of the bottle i’d poured it into, and forgot about the other one.
Yesterday, while looking through my fridge for something to eat, I found the other bottle, which had been standing in the back of my fridge for almost a year. Being as I had no other beverages around, I decided in the name of science to crack it open and give it a try. My first discovery was that it was EXTREMELY carbonated - I had to just barely open the cap and let it vent for about 15 minutes before I could take it off the rest of the way. Once I could pour myself a glass, I discovered two things. One, that it had become much dryer than it had a right to be, and that it had a vaguely familiar aftertaste. A couple more swigs and a few minutes later, I came to a conclusion; my drink had fermented somewhat and I had cola-wine. And it was weird, but it wasn’t all that bad.
I ended up drinking the entire thing that day. It couldn’t have been very strong - no more than 2-3% ABV probably. In retrospect, it makes sense that it would have happened - yeast + sugar + time = alcohol, which is probably why the instructions with the kit said to refrigerate the stuff after 2 days and drink it within a week. Keeping it in the fridge no doubt slowed down the process, but didn’t stop it entirely.
As drinking it neither made me throw up nor go blind, I’ve started to wonder how I could go about deliberately doing what i’d done by accident. I know pretty much nothing whatsoever about home brewing - would it be possible for me to brew an alcoholic cola that was stronger than my fridge bottle, say 5% or 6% ABV? Would I need any special ingredients or tools above and beyond what I probably already have in my kitchen? How long would it take?