Syneresis represents the appearance of separation of whey on the surface of the product and is considered an important parameter of the quality of fermented dairy products. For the production of the fermented milk drink, kombucha was used as a non-traditional starter. Two sweeteners were used, honey and sucrose.The aim of the work was to examine the influence of starter and sweetener on changes in the subsequent acidity and intensity of syneresis of the samples during storage. The results were compared with a control sample obtained by inoculation with a conventional starter culture. During storage, there was a drop in pH value and an increase in titratableacidity, as a resultof the constant metabolic activity of the microflora and the production of lactic acid in the produced samples. Honey, as a sweetener, had an effect on the lower pH value of the fermented milk drink samples. The analysis of variance showed a statistically significant difference in the titratable acidity results and the intensity of syneresis of the samples during storage.Samples that were produced with kombucha as a starter showed better structure stability during storage and better quality. During storage, sample kb4 showed the best structural stability and the lowest intensity of syneresis. KEYWORDS:stinging nettle extract;bioactive components;extraction;antioxidant