Fruit growing
and viticulture of South Russia

Annotation

In modern wine-making, a concentrated grapes must, including rectified must, is widely used to provide the necessary conditions for the content of sugars in the production of semi-dry and semi-sweet table wines. This product is also allowed to use at the wort stage to increase the alcohol content of wines, in the case of unfavorable weather conditions, when the mass concentration of sugars in the grapes is not sufficient. However, often instead of grapes concentrated must the surrogates or falsifications are introduced in the market, the use of which is forbidden for the wine production. The purpose of this paper is to analyze the information presented in various documents and literature on the quality indicators of grapes concentrated wort and methods for their control. The Institute "Magarach" is working on the study of the grapes must concentrated to search and justify the indicators, used for identification of its origin. It is shown that the share of such indicators as the proportion of tartaric and citric acids in the total amount of acids, and the content of sucrose in the total amount of sugars, and the ratio of glucose / fructose content differ in the samples of grapes and non-grapes origin. The normative documents of Russia, and the European Union and the International Organization of grapes and wines devoted to methods for assessing the quality and authenticity of grapes juices and concentrated worts are analyzed. The additional indicators for control of grapes origin and quality of concentrated grapes must are selected as the profile of organic acids and sugars, pH, electrical conductivity; content of sorbic and benzoic acids and their salts, hydroxymethylfurfural.

Annotation

Stabilization of wine means the removal of causes that provoke sediment formation in it, and giving stable transparency to the beverage during the warranty period using various technological operations. The aim of this work was to assess the impact of various technological methods at the stage of must (acidification with organic acids (citric, tartaric and malic), as well as must clarification with bentonite) on the tendency of base wines to crystalline haze and morphological features of crystalline sediment. The object of research was white dry base wines produced from the autochthonous grape variety Kokur Belyi, cultivated in the Republic of Crimea. It is established that the method of must acidification by adding citric acid provides a significant decrease in the temperature of saturation with calcium tartrate by 4.6 times compared to the control. Processing of must with bentonite also contributed to a decrease in the Tsat (�aT) indicator by 33.5-44.9 %. It was shown that methods of must acidification with tartaric acid, as well as must clarification with bentonite, provided a stabilizing effect towards crystalline calcium haze for young wine to the end of experiment (3 months). The characterization of crystalline sediment by visual assessment and microscopy showed that potassium bitartrate was present in all tested samples. At the same time, the volume of sediment and morphological features of crystals were significantly different: in experimental variants with introduction of citric, tartaric and malic acids, as well as in the control sample, an abundance of small transparent crystals of potassium bitartrate, which resemble �crushed glass� in shape, was observed. Presence of large crystals was noted in samples with introduction of bentonite at the stage of must, as well as malic acid in the amount of 2 g/dm3 . The results obtained are intended to support preventive measures in the production of wines to ensure their stability to crystalline haze.