2 tbsp. sugar
1 tbsp. vinegar
1 1/2 tsp. vanilla extract
10 oz. cold water
1/2 tsp. baking soda

Combine sugar, vinegar, vanilla extract and water into a 12 ounce or larger glass. Hold glass over sink as you add the baking soda, stirring briskly, as it foams. Drink immediately as tastes best while it is fizzing.