In this study, the effect of acid whey on the physicochemical properties and nutritional value of non-nitrite organic fermented sausage made from beef and tallow was investigated. Fermented sausage was prepared in three formulations: C (cured), S (salted) and SAW (salted with liquid acid whey). Each sample was analysed during the ripening process: at 0, 7, 14 and 21 days of ripening in a temperature of 16 °C. The obtained results indicated that the addition of acid whey improves physicochemical properties of organic dry-fermented sausage without nitrite and its nutritional value. The application of acid whey resulted in a significantly lower pH and a higher lactic acid bacteria content in organic fermented sausage without nitrite than in the sample with curing salt (respectively, by 0.12 units and 0.66 log CFU g−1). Acid whey successfully protected against haem iron loss in salted sausage during ripening. The salted sample with acid whey addition was characterised by a higher PUFA content (6.41%) at the end of ripening as compared to the cured sample (4.91%) and salted sample (5.58%). The addition of acid whey improves organic dry-fermented sausage without nitrite production and its nutritional value.