The objective of this study was to compare the quality of rye breads made of dough obtained using a one-phase method, and by applying various baking leavens. The analysis of physical chemical parameters (moisture content, acidity, protein content, falling number, and amylolithic properties) of the rye flour used, its type being 720, was performed using the methods generally applied in the grain milling laboratories. The dough yield and acidity of the dough were also determined. The dough was 35 minutes baked, at a temperature of 230 °C. Twelve hours after the baking process accomplished, the acidity and volume of bread, expressed per 100 g of bread, were measured, and the yield and baking loss were calculated. An sensory assessment was performed, too. On the basis of the sensory assessment and the values of physical-chemical factors, it was proved that the baking properties of rye flour, its type being 720, were accurate. The addition of water in the dough developed depended on the baking leaven, therefore, the yields of the doughs varied. Comparing with the dough acidified using a lactic acid (control sample), the yield of the dough with a leaven added in the form of paste (Uldo Sauer) was by 15 % higher . The acidity of the doughs developed was also different, and the dough with Uldo Sauer leaven had the highest acidity. The bread produced using the pasted Uldo Sauer leaven showed the highest yield and volume. The bread made using Flintbeker Sauerteig leaven showed the lowest baking  loss. The application of leavens caused the acidity of crumb bread to grow, and this fact favourably impacted the sensory assessment. Based on the study results, it was confirmed that the leavens had a favourable effect on the yield and volume of bread, thus, on the improvement in the bread crumb. The bread baked using the Uldo Sauer leaven was characterized by the best taste and smell values.