The passage of time and the experience of the wine growers and producers
have made possible the natural selection of those varieties of grape which
were best able to adapt to Riojan soils and climate, and which, at the same
time, were able to produce wines of the highest quality. The fruit of this
historical process are the seven varieties of grape which are currently
permitted by the regulations of the Denominación de Origen Calificada Rioja.
