The primary use of grenadine is to color a drink, which is most evident in a Tequila Sunrise. The Tequila Sunrise is yet another drink in the long procession of cocktails born during the Prohibition era. Marion Gorman and Felipé de Alba, in The Tequila Book, suggest that the Tequila Sunrise was invented at the Agua Caliente racetrack for Californians who spent the night betting on the horses while drinking too much. The cocktail was considered to be a morning pick-me-up for the bettors—hence the name Tequila Sunrise. While absolutely plausible, the story may be just one more instance of the need to historicize a cocktail.
To tell whether a Tequila Sunrise is made right, watch the glass. Because of grenadine’s specific gravity, it will begin to settle in the bottom of the glass beneath the glowing orange juice, a phenomenon that could have easily inspired its name. There is also a Tequila Sunset, which seems to have nothing to do with either theory of origin.
The trick to making a Tequila Sunrise work is all in the pouring. Think of it as a larger, and more salubrious, Pousse Café. Pour the ingredients slowly, and never over ice, or you will lose the effect. Therefore, chill the tequila first. If you decide to shake, omit the grenadine from the shaker and add it later. White tequila is always used.