Olive oils developed and bottled in the municipalities of la Rioja Alta, Rioja Media, Rioja Baja, Sierra de Rioja Alta, Sierra de Rioja Media and Sierra de Rioja Baja. The varieties allowed are redondilla or redondal, arbequina, empeltre, macho or machona, negral, royal or royuelo, hojiblanca, arroniz, verdial, picual, cornicabra, manzanilla and blanqueta, while the use of genetically modified ones is prohibited. Of an experimental nature, varieties such as arbosana, koroneiki, chiquitita and frantoio are also available. Fruity with some peculiar and soft hints of a bitter flavour, olive oil from La Rioja consists of many different characteristics. The difference comes from the particular climatic conditions and the soil type of the region. See Regulations