Chablis is Burgundy's northern most region spanning 3,000 hectares centred around the town of Chablis itself in the départment of the Yonne near Auxerre. Though considered part of Burgundy, in terms of geography it is as close to Sancerre and Pouilly Sur Loire as it is to the Côte d'Or, and in terms of soils and climate is actually closer. The vineyard area rolls around Chablis itself and 19 other villages. There are four levels of wine: Petit Chablis; Chablis;Chablis 1er Cru and Chablis Grand Cru, the latter of which there are seven which sit prominently above the town of Chablis itself on sun-blanched south-facing slopes.
Soil is a very important factor in the quality and unique style of Chablis and can roughly be divided into two types, firstly Kimmeridgean. This is a kind of clay limestone with a large proportion of fossilized oyster shells. Chablis is on the edge of the Paris rock basin the other side of which is the Dorset village of Kimmeridge from which the soil takes its name. The other soil type is Portlandien, a similar clay limestone structure without the same complexity, giving wines of slightly less sophistication and finesse. The former is the base of the Grands Crus and all of the best Premiers Crus and Chablis Villages vineyards, the latter, generally speaking, is the base for most of the outlying Petit Chablis area.
The northerly climate obviously means that vintages can vary quite starkly, summers are mostly hot and sunny, though, with the variation in weather coming more into to play towards the end of the season. The greatest danger during the season is from frost, which can be devastating, so much of the vine-growers early season activity is spent devising ways to protect the vines. One of the more traditional is lighting "smudge pots" throughout the vineyards, in an effort to get warm air circulating around the vines. The quantity and quality of wine produced can therefore vary from year to year. Chablis is obviously a large area and now a very big commercial brand so there are swathe's of rather poor quality and not very good value example around. Fortunately though there are plenty of fine examples, too. At its best Chablis is a unqieuly steely mineral wine that can age extremely well. "Classic" Chablis as we know it today is aged and fermented in steel tanks. However there are a number of growers experimenting with oak, mainly used barrels, not to give any oak flavour to the wine but to improve its texture and complexity. These can make for some of the very finest examples of Burgundy there are. Some of the finest exponents are Vincent Dauvissat, Francois Raveneau, Laurent Tribut, Droin and Moreau Naudet.