It takes a remarkably diverse region to produce a wine this special.

From a geological perspective, the Karst is a world of its own. Located in southwestern Slovenia and extending partly across the border to the Gulf of Trieste in Italy, the Karst Plateau is referred to among geologists as the Classical Karst. The region is largely defined by water-soluble limestone. This led to the first systematic cave explorations, laid the foundations of karstology, and gave names to many of the peculiar karst phenomena. Their formation resulted from varying climatic conditions throughout geological history, while today the Karst is shaped by a mix of Mediterranean and continental climates: strong bora wind, cool nights, abundant sunshine and warmth, sufficient rainfall, yet frequent droughts due to the soil composition and the porosity of the rocks.

On this rocky plateau, forced to survive without surface water, the people of the Karst learned to live. From a seemingly harsh and barren landscape arose a unique cultural landscape, one of the oldest in Europe. Stone was used as the main construction material and the sparse patches of soil that nature had provided were carefully cultivated and protected. And long ago, man also started cultivating domesticated grapes.

The special red soil of the Karst.

A defining feature of the Karst plateau is its carbonate soils, specifically limestone on which, over millions of years, a red soil (known as terra rossa or jerina) formed. Scientists believe that this red soil is the result of long-transformed sediments of clay and silt, containing significant residues of insoluble limestone and dolomite, along with various impurities. Among these, the presence of quartz plays an important role, influencing the soil’s chemical and physical properties, while iron oxide gives the soil its characteristic red colour. From limestone deposits of different geological ages, two primary types of karst soil developed, differing mainly in depth and quartz content.

Karst soils are heavy yet well-draining and airy. And in dry summer months they can become parched. Research shows that moderate drought stress increases the content of red pigments, a hallmark of Teran wine. Thanks to the unique structure of the Karst soils, vine roots can grow deep into cracks in the limestone, reaching water sources far below. Yet another remarkable feature of the Karst.