Cristalino translates as “crystalline” in Spanish and refers to oak-aged Tequila that's been filtered through charcoal, removing the naturally occurring colours the spirit has absorbed from spending time inside a cask. As the name suggests it's generally crystal clear although some still have faint tinges of straw-like colour.
Due to the choice of carbon used by the distilleries, the aim of the filtration process is to strip a lot (if not all) the colour, reduce some of the tequila’s woodier notes, but to be deliberately less aggressive in removing the textures and vanillin like compounds imparted by the barrel. As a result, Cristalino is a hybrid style of Tequila, combining the barrel aged flavours of an Añejo (such as caramel, vanilla and oak), and the rawer Agave notes present in a Blanco, while also offering a rounded mouthfeel and smooth texture.