Modra kavčina, also known as Žametna črnina, belongs to a Black sea eco-geographical regional species called Proles pontica Negr. According to Turković, it originated from our territory. Most likely this is our old domesticated variety.
Some time ago, in Styria, the variety was known by other names such as Blauer Kölner, kavčina, velika modrina, velika plava (large blue), velika črnina (large blackness), among others. In the past, Modra kavčina had been quite widespread on trellises and vineyards in Styria, especially in the Dolenjska Region; it is still grown in the northwest of Croatia and to a lesser extent in Germany and Austria.
The leaf has five parts, its surface is corrugated, and in the lateral notch it is shaped like a typical tooth. It fascinates us with its beautiful large clusters and large, round dark blue berries, which is also nice for cogging. The berries have a thick skin. The juice is sweet, colourless and has a pleasantly sour taste.
The Žametna črnina is a very late variety (meaning it ripens in the fourth ripening stage), its clusters weigh from between 250 to 400 g and more. Such heavy clusters are rarely given by any variety in Slovenia. It bores abundantly and it is a typical "mass producer.” In normal years, it obtains 14 to 17% of sugar content and 8 to 10 ppt of acid.
Žametna črnina makes a simple, light red wine of pure colour, which is suitable for mixing (combining) with other varieties and the production of highly-reputed wine varieties, such as Cviček from the Dolenjska Region, Gorjanska črnina, Metliška črnina, and red wine from Bizeljsko. Žametovka enhances the character of those types of wines by its colour and acidity and a very nice primary aroma (raspberry like). However, only under favourable weather conditions in the autumn does this wine give this characteristic colour to the wine. It rarely occurs independently on the market. In the Official Assortment of Slovenia, it is recommended as the variety to be grown in Bizeljsko - sremiško, Dolenjska, and Bela Krajina wine-growing districts in the Posavje wine region and as a permitted variety for the Maribor district and the districts of Slovenske gorice and Šmarje-Virštajn in the Posavje wine region.
In Ampelography (1841), Franz Trummer wrote, while describing Styrian grape varieties, that "Modra kavčina has been known in these parts for a long time. We find it especially on the façades of houses, on trellises, where it is not an uncommon vine and they can boast of a length of up to 30 meters. They bring rich harvests to their owners."
In 1878, Herman Goethe, director of the viticulture school in Maribor, wrote in his ampelography that the "Modra kavčina has been known in Styria and Carniola for a long time, as is evident by the ancient vines on trellises next to houses". Even during the first half of the 20th century, some very old vines grew profusely on the façades of town houses in Maribor. Especially famous were the two vines at the Maribor Water Tower and the city castle.