<P> The Chablis wine region has much in common with Champagne province, when it comes to climate . It has a semi-continental climate without maritime influence . The peak summer growing season can be hot; and wintertime can be long, cold and harsh, with frosty conditions lasting to early May . Years that experience too much rain and low temperature tend to produce wines excessively high in acidity and fruit that is too lean to support it . Vintages that are exceedingly warm tend to produce fat, flabby wines that are too low in acidity . Frost can be countered by heaters, and aspersion by sprinklers to form an ice layer . The exceptionally poor 1972 Chablis suffered frost at vintage time . </P> <P> The region of Chablis lies on the eastern edge of the Paris Basin . The region's oldest soil dates back to the Upper Jurassic age, over 180 million years ago and includes a vineyard soil type that is calcareous, and known as Kimmeridge Clay . All of the Chablis Grand Cru and Premier Cru vineyards are planted on this primarily Kimmeridgean soil, which imparts a distinctively mineral, flinty note to the wines . Other areas, particularly most of the Petit Chablis vineyards, are planted on slightly younger Portlandian soil, still of similar structure . The chalk landscape resembles some areas of Champagne and Sancerre . </P> <P> A serious viticultural concern for Chablis vineyard owners is frost protection . During the bud break period of a grapevine's annual cycle, the Chablis region is vulnerable to springtime frost, from March to early May, which can compromise the crop yield . Formerly, the financial risk involved saw many producers turn to polyculture agriculture, pulling up vineyards to plant alternative crops . The 1957 vintage was hit particularly hard by frost damage: the regional authorities reported that only 11 cases (132 bottles) of wine were produced . </P> <P> In the 1960s, technological advances in frost protection introduced preventive measures, such as smudge pots and aspersion irrigation to the region . Smudge pots work by providing direct heat to the vines while aspersion involves spraying the vines with water as soon as temperatures hit 32 ° F (0 ° C) and maintaining persistent coverage . The water freezes on the vine, shielding it with a protective layer of ice that functions igloo - style, retaining heat within the vine . While cost is a factor in using smudge pots, there is a risk to the aspersion method if the constant sprinkling of water is interrupted of causing worse damage to the vine . There is no such protection against hail, which in 2016 caused serious difficulties for some Chablis vignerons . </P>

French chablis are made from the same variety of grapes as the following wine(s)