1800 tequilas are made by Casa Cuervo from 100% blue agave. The name comes from the "historic event" of aging tquila in oak for the very first time. The line was first launched in 1975 as a premium sipping tequila. 1800 Reserva Silver tequila is a blended tequila that includes a 15-day aging in American oak plus a 'touch' of blending with other aged tequilas. As a result, it has a pale yellow color unusual for silver tequilas.