The bunch is large, cylindrical-conical and compact. The grapes are dark-blue to bluish-black and their skins are thin and frail. Gamza is a late-ripening variety – it ripens at the end of September or beginning of October. However, in the Vidin area in north-western Bulgaria, the grapes achieve technological maturity earlier – around September – because the accumulation of sugar is more intense. In general, Gamza thrives best at windy hills with rich soils. Because of the thin skin of the grapes, they are prone to developing fungi such as grey mold. For instance, if the autumn is quite humid, the grapes tend to get this disease. Thus, Gamza requires a warm and dry autumn in order for the wines to be of good quality. Gamza is not particularly resilient to low winter temperatures, although it prefers cooler climates which is the reason why it is mostly cultivated in northern Bulgaria.
The temperate continental climate in the area and the favourable distribution of precipitation are good premises for the developed red wine growing in the lowlands of Upper Thrace. The region includes the central part of the lowland, as well as parts of the Sakar mountain. Mavrud, a famous local wine, as well as Merlot, Cabernet Sauvignon, Muscatel and Pamid are grown.The Balkan Mountains serve to block the cold winds blowing from the plains of Russia, and the region to the south of the Balkans, the valley drained by the Maritsa River, has a Mediterranean climate, with mild, rainy winters and warm, dry summers. In the US appellation also approved as Thracian Valley region.
