Karst, the Home of the Teran Wine with a Recognized Traditional Denomination

THE KARST PLATEAU IN SLOVENIA AND ITALY

The Karst plateau is the home of the teran wine with a recognized traditional denomination, i.e. the Teran PTP in Slovenia, and the Terrano wine in Italy. It spreads into both countries, and is bordered by the Gulf of Trieste, the Vipava valley, the valley of the Isonzo river, and the Brkini hills. With an average altitude between 200 and 400 meters the Karst plateau has a somewhat harsher climate, which, together with the carbonate rockbed and the silicate and iron rich terra rossa, provides for special growing conditions. In the Karst they shape a characteristic and globally unique terroir for wine growing.

Today there are 590 hectares of registered vineyards in the Slovenian Karst, and 400 hectares on the Italian side. The Karst is also the home to the traditional variety of the "kraški latnik" vine training system, however its use is now in decline .

The recommended grape varieties for cultivation on the Karst plateau in Slovenia are malvasia and refosco, with the latter accounting for about 80% of the cultivated area. Karst’s special geoclimate conditions result in refosco variety turning into Teran (PTP) in Slovenia, and Terrano in Italy. Teran PTP and Terrano are special phenomena of global viniculture.
In Slovenia teran is protected with the recognized traditional denomination (PTP) in accordance with the Rules on Wine with the mark of recognized traditional denomination – teran (Official Gazette of the Republic of Slovenia, no. 16, 15 February 2008). The Teran PTP wine is produced only from refosco variety grapes at absolute wine growing locations of the Karst wine growing region, i.e. the Trieste-Komen plateau, which stretches between the left bank of the Vipava river on the north and the Gulf of Trieste on the south, the Isonzo plain on the west and Ilirska Bistrica on the east. The soil created from the limestone decay or dissolution contains higher levels of the skeletal quartz, and is also called quartz. The higher levels of skeletal quartz contribute to the soil’s higher acidity, and thereby also towards these specific conditions for producing teran wine. Because of the frequently red color of the soil it is also referred to as terra rossa, Italian for red soil. The absolute locations of vineyards are airy, so that they do not lie in the depressions of the sinkholes.
For Teran PTP the refosco variety grapes are produced according to the instructions for integrated grape production with the “kraški latnik” or “šparonska” vine training systems.

According to the definition in the Rules, Teran PTP is a red, dry, still wine with a moderate alcohol level, and the nose and taste of berries. The color of Teran PTP is intense, ruby red, and may contain violet tinges. Teran PTP has a characteristic higher content of lactic acid, and other organic acids and polyphenol compounds, especially red pigments and anthocyanins. The intense red color and freshness of the Teran PTP is further accentuated by the higher levels of acids, compared to other red wines. Teran PTP is a dry, full bodied wine with a lot of freshness and notes of minerals.

The stark red color and the lower level of alcohol make Teran PTP a healing wine. The carmine red is the result of a high level of biologically active red pigments, called anthocyanins. It has been proven that they prevent the onset of cardiovascular illnesses, as they help prevent arteriosclerosis, and lower the harmful low-density lipoprotein cholesterol. Anthocyanins also pass into our brain cells. According to studies that have been conducted so far it is believed that they have a beneficial effect on the brains, and help prevent the onset of neurodegenerative diseases. Anthocyanins also have anti-carcinogenic properties. They also have a positive effect on preventing the onset of metabolic syndrome and diabetes, as well as on the eyes, as it has been proven that they strengthen the walls of capillaries in the eyes, improving their flexibility.

One of the basic objectives of the Agrotur Project (which also includes the establishment of the Hotel Dobrega Terana) is to study the wine growing technologies with the goal of selecting the most suitable approach in a vineyard to improve the quality of the Teran PTP and Terrano wines. We would like to unify the wine-growing technology among individual producers for brand optimization. The other aspect requiring optimization alongside the wine-growing technologies is that for producing wine. We have to be especially mindful regarding the time of harvest, the health of the grapes, the correctly handled maceration and the microbiology. Since according to the Rules, Teran PTP is a wine which requires biological deacidification, we will place greater care on the suitability of the conditions for biological deacidification (adding a pure culture, the level of cleanliness in the cellar).
Another of the project’s goals is to study the quantity and the profile of the polyphenol compounds in the refosco grapes and the Teran PTP and Terrano wines. Tannins and anthocyanins affect the wine’s aroma and color, but they are also compounds with healing effects. We will study the potential of the refosco variety grapes in the Karst, with the goal of obtaining clear data on which type of vinification is required for these grapes. At the same time the information on the above average levels of anthocyanins in the Teran PTP and Terrano wines is very important for determining the wine’s effects on health, and can serve as a strategy for promotion.

More information on this project is available at: www.agrotur.si