As an Amazon Associate I earn from qualifying purchases. A Gibraltar is a double shot of espresso topped with warm, lightly steamed milk and served in one particular glass: the Libbey Gibraltar, a small, heavy-bottomed rocks tumbler that holds 4.5 ounces, about 130 ml. The name comes from the glass. Serve the same drink in a ceramic cup and most baristas would call it a … [Read more...] about Gibraltar Coffee: San Francisco’s Cortado, Named After a 4.5-Ounce Glass