The bitterness in roots of ten red beet cultivars was assessed in the study. Beets of cv. ‘Ceryl’, ‘Chrobry’, ‘Czerwona Kula Noe’, ‘Nochowski’, ‘Noe 21’, ‘Noe 694’, ‘Noe 799 Tytus’, ‘Noe 804’, ‘Okrągły Ciemnoczerwony’ and ‘Opolski’ after their morphological description were subjected to sensory examination to detect bitter taste, after which juice was made and again sensory analysis was conducted. Moreover, bitterness of juice was assessed after it was subjected to the technological processes of pasteurization, condensation and souring. On the basis of results of sensory analyses of individual parts of roots and red beet juice the most bitter taste was detected in cv. ‘Nochowski’, ‘Chrobry’ and ‘Okrągły Ciemnoczerwony’. All those cultivars were characterized by a round flattened shape of roots. The bitterest part of red beets was their peel, followed by the root head and root base, while the centre was least bitter. Pasteurization had a slight effect on the sensation of bitter taste in juice, bitterness remained at a level similar to that of raw juice and did not change significantly with the extension of pasteurization time. Juice condensation enhanced the sensation of bitter taste, while souring completely eliminated bitter taste in the assessed juice of all cultivars.