This is photo of the Prosperina Margarita, invention of super-intense Canlis bartender James MacWilliams. Up front is the cocktail right after it was mixed, the one behind it was taken after five minutes, the one behind that after 10, the one behind that after 20.
A mixture of tequila, St Germain, simple syrup and lime juice, the cocktail comes topped with something MacWilliams calls “Persephone foam.” If you’re looking to make your own color-changing mixed drink, here’s some info from the mad scientist himself: "The primary component in this reaction is the Persephone foam. Phenolphthalein is an acid base indicator found in many fruit skins, in this case pomegranate and blueberry juice.
If the solution is alkali above 9.6 pH, it remains clear, while acidic or below 8 pH, it becomes pink. The green color in the foam is the color of the plant matter in the juices without coloration from phenolphthalein. The transformation occurs when the foam is mixed with the lime juice and St. Germain, both of which are acidic. Without revealing all my secrets, the trick is the addition of a common supplement found and most vitamin stores and some processing."
The prosperina costs $12 at Canlis. So what do you think: gimmick in a glass or scientific genius?