Sémillon is a grape that is most famously used in white wines from Bordeaux. It is usually used in conjunction with other
grapes, as it lacks sufficient punch to make a good varietal.
In French, Sémillon has an acute accent on the e. This is
necessary for pronunciation reasons — without the accent, the first
syllable would be pronounced 'suh' rather than 'seh'. In some English
dictionaries1, Sémillon is listed with an accent; in
others2, it is listed both with and without. On wine bottles, the
accent is always present on any French wine that deigns to list the grapes used,
usually present on South American wines and infrequently present on North
American and antipodean wines.
There are four ways in which Sémillon is commonly used:
As an addition to Sauvignon Blanc. This is the mix
used for many dry white Bordeaux wines, and it has also become popular in
the new world. The Sémillon will round off the flavour and help take some
of the steely bite off the Sauvignon Blanc.
As a very sweet white dessert wine, usually blended
with some Sauvignon Blanc and possibly Muscadelle. This is the sweet
white Bordeaux mix, used in the famous Sauternes and the less well known
and far more sensibly priced Graves and Barsac.
To tone down Chardonnay. Although the Chablis
pure Chardonnay style can be extremely impressive, it requires a particular
climate and type of land to work well. For producers not fortunate enough to
own prime Burgundy terrain, some of the inevitable edge can be taken off
using Sémillon as a second grape. This will lead to a slightly sweeter,
rounder wine that is substantially easier to produce.
On its own, as a medium sweet white. These wines
don't tend to work particularly well — Sémillon lacks the gravitas to
stand on its own effectively. None the less, it is sometimes produced this
way in Chile, South Africa (where it is known as Wyndruif) and in some
of the less reputable Australian vineyards.
The grape is not especially hard to grow; this at least
partially explains its popularity in blends, where it can mask imperfections in
other trickier grapes. The very sweet Sauternes style, however, is
extremely difficult, as it relies upon the grapes being rotted by botrytis cinerea to remove most of the moisture.
Sémillon is typically described as tasting of figs or
grass cuttings; the Sauternes style, however, can only be described in terms of itself, and is thus immune to the usual peculiar descriptions.
Depending upon how it is mixed, dry Sémillon can make a good accompaniment to
seafood or chicken. The semi-sweet and dessert varieties go well with
cheese and fruit.
1: Collins English Dictionary
2: The American Heritage Dictionary of the English Language, 4th Ed.