Ingredients: 2 cups water 1/4 sugar 1 tablespoon vanilla extract 1/16 teaspoon active brewing yeast Allow to ferment at room temperature for 2-3 days in a tightly sealed bottle. This time will vary widely depending on temperature, and I strongly recommend finding a length of time suited to your environment and tastes with a plastic bottle before trying this with glass. Even after testing the recipe with plastic, I still placed my glass swing top bottle in a paper bag. Chill throughly in the refrigerator and open over a sink or outdoors, just in case of a fizzy mess, and enjoy cold. Don't leave leftover soda in a sealed container for too long. It will continue to build up pressure and may burst the bottle.