Many recipes for elementary science activities suggest making carbon dioxide from baking soda and vinegar; however, they often do not give exact measurements of the ingredients. The author was able to turn this “drawback” into a plus by challenging her fifth-grade students to find the ultimate fizz—i.,e., “What amount of baking soda added to a set amount of vineagar gives the maximum reaction without having leftover baking soda?” As students investigated this question with enthusiasm, graphing and measurement skills developed in the process.