Semillon is a white grape used to produce white wines throughout the world, most often in concert with another grape. It has had a difficult history in its treatment by the wine-drinking public, and has been vilified among so many wine connoisseurs that many winemakers do not put the name Semillon on their labels.
In France, Semillon is one of the major grapes used to make white Bordeaux wines, alongside Sauvignon Blanc. These wines nearly always blend Semillon, but the ratios depend entirely on the chateau responsible for the wine itself. Some white Bordeaux wines are primarily Sauvignon Blanc, resulting in a full-bodied, dry white wine – these are the sorts made in the regions of Pessac-Leognan and Graves. Other white Bordeaux wines are primarily Semillon, with just a bit of Sauvignon Blanc added for acidity, resulting in a wine that is much sweeter than most whites.
In Australia, the Semillon grape has the distinction of being taken seriously as a grape that can be used to produce respectable wines. As a result, many Australian vineyards produce wines that are exclusively made from Semillon. These Australian Semillons are dry and heavy, and ideal for aging. A good Australian Semillon turns nearly orange over the years, and can prove to be an amazing opportunity for a unique and exquisite wine. These higher-quality Semillon wines take some getting used to, mostly because of the taste variously described as burnt toast or volcano – a strange mineral taste that some find rather a turn-off at first blush.
Australia also produces Semillon wines in the style of the French Sauternes sweet wines, as well as blended Semillon wines intended for more mass consumption. These blends usually mix the Semillon grape with either Sauvignon Blanc or Chardonnay, or both, to lend a bit of acid to the resulting wine. Semillon is one of those white grapes that lends itself well to the noble rot of botrytis, increasing the sugar content in the grape on the vine and creating a very sweet dessert-style wine. The Sauternes region of Bordeaux is most well-known for their variety of sweet Semillon, though other regions also create them. These Sauternes wines are widely hailed as some of the best sweet wines in the world, and many connoisseurs suggest pairing them widely with food – not simply with desserts.