If I was a planner, which we all know I'm not, I totally would have made some beer.
I looked around a bit and it seemed to be fairly simple. You'll need:
an empty 2 liter bottle
1 c sugar
1 Tablespoon + 1 teaspoon root beer extract
1/4 t yeast
To start, place a funnel in the top of the bottle. Add sugar and yeast.
Add in about 3 cups of water and mix well.
Finally fill the bottle to almost the top. You'll want to leave about 1" to 1 1/2" headspace. Tighten cap and let sit at room temperature until you can no longer squeeze the bottle. Depending on what kind of yeast you're using, it could be 6 to 48 hours. I used Red Star Quick Rise yeast, so it took just about 6 hours for the bottle to be ready. See all the carbon dioxide bubbles formed by the yeast?! That's how this root beer gets the carbonation.
When you can't squeeze the bottle anymore, refrigerate over night. Now it's ready to drink!
If root beer isn't your drink of choice, what about ginger ale?
To make ginger ale, you'll need:
2 T fresh grated ginger
1/4 teaspoon yeast
juice of one lemon
1 c sugar
Pour sugar and yeast into bottle. Swirl around. Mix the ginger and lemon juice together to make a slurry.
Add slurry to the bottle. I used a kabob skewer to push it through my funnel.
Add water and shake bottle until mixed. Let it sit out at room temperature until you cannot squeeze the bottle. Refrigerate over night. Enjoy!