A couple months ago, we decided to attempt to make root beer. The soft drink isn't difficult to make. All we had to do was heat a gallon of water, add root beer flavoring and activated yeast, and then put the liquid in two two-liter bottles to sit for about two weeks.
Part of the two weeks is spent in a warm place until the bottles are completely full of carbon dioxide from the yeast and they have no give. This is when the bottles can burst. If the bottles sit too long in the warm place, they will overfill with carbon dioxide and explode.
Once they were full of CO2, we placed the bottles in a cool place for a week. When the week was up, we put them in the refrigerator to get cold. Once it was cold, we all tried the root beer. I thought it tasted bad. The root beer was way too strong and left an odd taste in my mouth.
Two weeks ago, we tried to make root beer again. This time the root beer came out a lot better. The aftertaste was gone and the root beer was a lot less strong.
Don't forget the sugar!