sidecar

A sidecar is a term for a small glass of sparkling water or seltzer served beside an espresso.The purpose of the water is to cleanse a person's palate before and after drinking an espresso shot. It is commonly associated with third-wave coffee and may be served by default alongside an order of espresso. Additionally there is also an espresso sidecar, which refers to a shot of espresso that is served alongside a cafe latte or cappuccino. In 2016, Starbucks launched a specialty beverage at some of their locations that included a beer, with an espresso sidecar meant to be poured into the beer. Etymology The term likely originates from bartending culture. If a bartender overpoured, and therefore ended up with more of a drink than will fit in the special glass for that drink, it was common for them to serve the extra in a small glass beside the drink. Meanwhile, it has become common to call anything served beside a drink a "sidecar". For example, a bar in Chicago serves a piece of chocolate with a mixed drink and calls it a "sidecar." Similarly, when diners serve milkshakes, there will typically be a little bit leftover that doesn't fit into a glass, this extra will be served alongside the milkshake in a metal mixing cup and is called a "sidecar."