Distribution of 13C/12C isotopes in vegetative (roots, grapevine, leaves) and generative (berries) parts of vine plants of the West European genetically different varieties Cabernet Sauvignon and Aligote growing on soils of Krasnodar krai and Rostov oblast, as well as autochthonous varieties Sibirkovy and Krasnostop Zolotovsky growing in Rostov oblast, has been studied using isotopic mass spectrometry methods. It has been shown that the variations of δ13C values in plant tissues and berries are related to the climatic conditions of plant growth: moisture (a sum of annual precipitation) and temperature (a sum of annual effective temperatures). The carbon isotope ratios of vegetative and generative parts of vine plants have been found to be noticeably affected by vine varieties. The different 13C contents in ethanol produced from wine of the Aligote and Cabernet Sauvignon varieties grown in two Russian vineyard regions are due to vine growth conditions, variety attribution and wine production techniques. An analytically significant parameter determined as exemplified by the Aligote and Cabernet Sauvignon varieties in fermentation of vine harvested in different seasons and in both vineyard regions was an increased 13C content in ethanol with respect to dry (non-volatile) residue in wine after distillation of ethanol. This characteristic has been determined by a systematic difference of about 1–2‰ between the δ13C value of ethanol and the dry residue. A relative constancy in the carbon isotope composition of ethanol and of the dry residue in the final product is the basis for determining the authenticity of grape wines by means of isotopic mass spectrometry irrespective of natural factors.