The vanishing valentine experiment is another chemical reaction related to the blue bottle experiment. This reaction occurs when water, glucose, sodium hydroxide, and resazurin is mixed in a flask. When the solution is shaken, it turns from light blue to a reddish color. The solution turns back to a light blue after being left to stand for a while. This reaction can be repeated several times.
After mixing all the components, shake the bottle and the color will turn to red or pink depend on the amount of resazurin in the solution. More resazurin will result in more time needed for the solution to turn back the color and the intensity of the red color.
The chemical reaction stimulates glucose to reduce resazurin to resorufin. It would then be reduced again into a colorless compound called dihydroresorufin. When dihydroresorufin is shaken, it is oxidized back to resorufin. This is due to the fact that shaking it results oxygen in the bottle to oxidized dihydroresorufin back into resorufin.