Kastelberg is a named vineyard of the Alsace Grand Cru appellation, meaning that Kastelberg may be used as part of the appellation title on wine labels. Located in the Bas-Rhin sub-region of Alsace, it is one of two Grand Cru vineyards in the commune of Andlau, along with its neighbor, Wiebelsberg.
Kastelberg's slopes cover only 15 acres (6ha), making it the second-smallest Grand Cru in Alsace – just larger than Kanzlerberg. The slopes rise steeply from 755 to 985ft (240–300m) immediately above Andlau, and are covered with sandstone-dominated, free-draining soils. The site faces due south, which means that its vines are fully exposed to sunshine throughout the day – a significant benefit in cooler years when grapes from other sites may struggle to ripen. In warmer years, Kastelberg's southerly aspect and steep slopes result in a rich, ripe style of wine.
The climate throughout Alsace is of continental type, with particularly low rainfall – a result of the rain shadow cast by the Vosges. The mountains also provide protection from the prevailing westerly winds, making the Alsatian summer amongst the driest and warmest in the northern half of France. At the other end of the temperature scale, the winters here are cold; it is not uncommon to see Alsace vineyards lined with snow.
Apart from a few notable exceptions, all Alsace Grand Cru wines are varietals and may be made from Riesling, Gewurztraminer, Pinot Gris or Muscat. Kastelberg specializes in Alsace's key grape variety: Riesling.
