In empty 1-L or 2-L soda bottles, place the following:
* 0% = 1000 g of water
* 5% = 950 g of water, 50 g of sugar, two drops yellow food coloring
* 10% = 900 g of water, 100 g of sugar, one drop blue, one drop yellow
* 15% = 850 g of water, 150 g of sugar, two blue drops
* 20% = 800 g of water, 200 g of sugar, one drop blue, one drop red