reflection, from soils and in some cases from water is considered by some to influence wine quality. Very white soils, such as the albariza soils of jerez, do indeed reflect high proportions of sunshine, and can add to the heating of vines growing on them. This is easy to demonstrate by calculation. More difficult to prove or measure is the theory that sunlight reflected from rivers may benefit nearby vineyards, as in the Mosel Valley. While the eye can behold the silvery sheen of water at low sun angles (specular reflection), it is unlikely that this can have any heating effect on adjacent vineyards.