Gumza (Gamza)
Gumza is an old local variety, cultivated in northern Bulgaria from old times. In Hungary, Slovakia, France, Romania, Yugoslavia, Austria and Turkey it is known as 'Kadarka'. Until recently it was a basic wine variety for the production of red wines in the northern vine-growing region. In other parts of the country it is cultivated as single vines in plantations.
The bunch is large (15.4/8.2 cm), cylindrical-conical, often single winged and compact. The grape is small (16.2/15.6 mm), almost spherical and, when the bunch is compact, deformed. Its skin is thin, frail, with a thick waxen bloom, dark-blue to bluish-black.
Gamza is a comparatively late-ripening variety - its vintage is at the end of September and at the beginning of October. The yield from one vine is 4-6 kg. The thin, frail skin of the berries, which cracks, if the autumn is humid and the grapes are strongly attacked by grey mildew is its big disadvantage. The yields and the quality lower considerably. To avoid this happening, the variety should be cultivated in airy, hilly regions with light drained soils and it should also be picked quickly.
When it is stem-cultivated, short fruit groups are recommended (nods) and, if the vine is very strong and the fertility of the lower eyes is low, mixed fruit groups with short fruit bearings. It is not very resilient to low winter temperatures. Its fertility is better when it is cultivated on rootstocks Shasla x Berlandieri 41 B.
When the variety ripens, it reaches 19-21.8% sugar content. In Vidin District the accumulation of sugar is more intense and the technological maturity occurs earlier - around 15th September. If the autumn is warm and dry, the red wines produced from Gamza typically have a vivid but not very dense ruby colour, a pleasant taste of small red fruits dominated by raspberry and a distinct but mild freshness and pleasant tannins.