For a school science fair last year, my friend and I studied the effect of temperature on carbonation. We used 30 bottles of 12oz. Coke and 30 bottles of 12oz. Pepsi. We exposed ten bottles of each soda to a cold temperature, 10 to a room temperature, and 10 to a warm temperature. We then placed small balloons over the tops, opened the bottles, and measured the size of the balloon every 30 seconds, three times.