Zafiro Añejo is a rare type of tequila, a distilled beverage made from the blue agave plant. Most notably, a bottle of Zafiro Añejo was poisoned by Gustavo Fring and later drunk by Eladio Vuente and other high-ranking members of the Juárez Cartel, causing their deaths ("Salud"). Añejo, meaning aged or vintage, indicates that the tequila was aged a minimum of one year, but less than three years in oak barrels.
Zafiro Añejo is a fictictious brand of tequila created by the writers of Breaking Bad. It was created after attempts to find a product placement fell through after being told that the scene contained people dropping dead minutes after drinking their placed product. The word zafiro is Spanish for sapphire and is a reference to the blue color of Walter White's meth.
Despite the drink being entirely fictional, the design of the bottle may have taken inspiration from the 140-year-old "Hardy Perfection Fire" Cognac. Only 300 Hardy Perfection bottles were ever produced, 60 each with the themes of air, earth, fire, water, and light. Each bottle costs about $7800.
Gustavo Fring, Mike Ehrmantraut, and Jesse Pinkman visit the cartel's hacienda after Jesse is acquired by the cartel. The cartel's leader Don Eladio Vuente spots the gift box that Gus has bought him and is delighted to see the premium tequila inside. Don decides to share the tequila with the rest of his cartel, and has his waiter pour shots for everyone except Gaff and Mike. Gus takes Jesse's shot back stating that Jesse is an addict and needs to stay sober to do his work. Poised for a toast, Don Eladio stops and warily eyes Gus. Gus drinks first, and the entire cartel also drinks the tequila. Gus asks to use the bathroom, and Don Eladio has a capo escort him there. Once in the bathroom, Gus begins to vomit the tequila he had drunk earlier. The entire cartel drops dead after being poisoned, and Don Eladio collapses in the pool. Gus begins to falter, as his pills he took earlier to protect him from the poison hadn't entirely worked ("Salud").