Solera by the producers of sherry. In a Spanish sherry "solera", the vintner may transfer about a third of each barrel a year. A solera sherry has to be at least three years old when bottled. A quite similar process is called sostrera, used to produce fortified wines in the Mediterranean regions of France. In Sicily, where Marsala wine is made, the system is called "in perpetuum". Solera vinification is used in the making of Mavrodafni ("Black Laurel"), a fortified red dessert wine made in the Northern Peloponnese in Greece. Exceptional "Mavrodafni" vintages are released every 20 or 30 years: they
White wine the technique of ice wine can produce exceptional wines in a climate which is apparently unfavourable. Canada is the largest producer of ice wine in the world. The warmer southern areas also produce white wine, but in a lower proportion. In addition, it is more often sweet or fortified wines, natural sweet wines or "vinés" wines, as in the case of vineyards around the Mediterranean (muscat, madeira, marsala etc.). According to Claude and Lydia Bourguignon, red wines are well suited to soil based on limestone while the best white wines are produced on soils over metamorphic rocks (Alsace, Moselle, Anjou)