The objective of the research study performed was to assess the effect of acid whey on the selected physicochemical properties and colour stability of the fermented pork sausage after ripening and after 7 and 14 days of refrigerated storage (4 ºC). The research material consisted of the ripening pork sausages with acid whey and sea salt added. Two variants of sausages were prepared: a cured control sample and a sample with acid whey and sea salt added. The assessment was performed immediately after ripening and after 7 and 14 days of refrigerated storage. During the tests, the following was determined: pH value, oxidation-reduction potential (ORP), TBARS index, and colour parameters in the CIE L * a * b * system after the ripening process (0) and after 7 and 14 days of refrigerated storage. During the research study conducted, it was found that the acid whey added significantly affected the increase in the acidity of sausages during the 14-day refrigerated storage. The cured control sample was characterised by a more stable level of oxidation and reduction potential. The studies did not show any significant differences in the TBARS index during the storage of sausages with the acid whey added, and the mean value was about 0.937 mg MDA/kg. No significant differences were reported in the colour parameters of the products tested. The sausages with the acidic whey added had the similar values of the L * a * b * colour parameters; however, the cured sausage was characterised by a higher colour stability (ΔE *) during the cold storage. Based on the results obtained, it has been concluded that it is possible to use acid whey derived from the Kuyavian-Pomeranian Voivodeship to produce the raw-ripening sausage without adding sodium nitrate(III).