Normandy Soils in Calvados Region

As it takes two hours to traverse the Calvados appellations in a car from north to south and four hours to drive from east to west, it should be evident that the soils vary greatly across the region. Soil perhaps plays less of a role with distilled spirits than it does for table wines. This is because spirits begin with a base matter that is converted into alcohol and distilled before aging in oak for an extensive period. All of these factors have an important effect on the finished product.

Time to gather colorful apples for calvados
at Domaine Dupont in the Suisse-Normandy.

But soil does play a role on a tree's growth as well as with an apple's acidity level and pH. The Pays d'Auge has high quantities of flint (silex) in addition to clay, and this stony soil makes the tree suffer, with many of the nutrients going to the developing fruit rather than the tree's wood. On the contrary, the Suisse Normande (located in the AOC Calvados region) has a lot of silty clay with some stone mixed in, and apples tend to have more acidity and a bit less sugar, which often leads to a more elegant spirit with purer apple flavor.

• Flint (silex): A sand-based soil type that is formed from a mixture of clay, limestone, and silca into hard, shiny green pieces.
• Clay (argile): Along with sand and loam, claty is one of three principal types of soil. Clay binds other kinds of particles together and retains water well. The soil is often very cool and high in acidity. Too much clay, however, makes cultivation difficult because it prevents free circulation of air aroudn the roots. The best clays occur in sediments and sedimentary rocks. These were generally inherited from adjacent continents and carried to the ocean by rivers and wind. Sedimentary rock-based soil has good water retention capability but poor drainage.
• Silt (limon:) A more fertile soil than sand, and constists of finely-grained deposits that offer godo water retention but mediocre drainage.

The Domfrontais region has more schist and granite-based soil in which pear trees thrive.

• Schist (schistes): A metamorphic rock that changes when under pressure. Most schist has been derived from clay and mud that has passed through a series of changes involving the production of shale and slate along the way. Schist retains heat well but is poor in organic nutrients and nitrogen. It often contains minerals like mica, chlorite, talc, graphite, and quartz.
• Granite (granites): A course-grained, light-colored, hard rock consisting chiefly of quartz, orthoclase, microcline, and mica. One of the most comme rocks of the Earth's crust, it is formed by the cooling of magma. It is often used in monuments for building. Granite allows much more water retention than dryer soils like schist, and water retention helps produce more fruit, albeit with a bit less sugar. This soil warms quickly and retains heat well.