Rodolfo and Charlotte tested the idea with a three-month pop-up at the O2 Centre in 2016, then ran temporary sites for five years before opening this permanent bar in January 2022. Gramos means "grams" in Spanish, and espresso beans are graded 85+ and filter beans 87+.
The bar is a curved glass kiosk in the station's ticket hall, opening straight onto the concourse, with no seating.