Those who frequent the bars around Carrer de la Mercè, a street that runs through Barcelona’s Gothic Quarter, are no strangers to panther milk. Known locally as leche de pantera, this dangerous beverage is—at its most basic—condensed milk, gin, and water or ice.
Spain’s elite military unit, the Spanish Foreign Legion, created panther milk in the 1920s. Some say General José Millán-Astray (the unit’s head and founder) tasked a locally-renowned bartender to develop a cheap, simple cocktail recipe his men could make and serve while stationed anywhere, from the seaside to the Sahara desert. Others claim that injured soldiers began mixing medical-grade alcohol with condensed milk while confined to infirmaries. Once the men returned to their troops, they shared the recipe and upgraded to gin, or whatever spirit they had on hand.
In the ensuing decades, panther milk largely disappeared. In the 1970s, however, it was resurrected by a newfound fervent fanbase: college kids. Around 1975, a former Spanish Legionnaire opened a bar called La Barretina in an alley along Carrer de la Mercè. There, he began whipping up chilled vats of the old favorite. Students flocked to this seemingly-newfangled knockout of a cocktail, which came cheap and premade. La Barretina’s neighbors quickly got wind of the trend as the area became inundated with youngsters.
The bar across the street, Tasca El Corral, hopped on the bandwagon by making a less potent, more palatable pink version. La Barretina has since shuttered, but the neighborhood’s “pink panther milk” (leche de pantera rosa) spot remains popular three decades later. A modern iteration might be comprised of a combination of gin, brandy, fresh milk, and condensed milk, and the top comes dusted with powdered cinnamon. It may be white or pink in color, but if you order the latter, don’t expect to learn the secret behind it.