Cheese whey is the most polluting by-product of the dairy industry, and whey use has been the subject of much research; however, the conversion of liquid whey into value-added yogurt products is insufficient. The aim of the current research is to study the effect of fermentation of a milk-liquid whey mixture into yogurt and strawberry supplementation on the syneresis index and textural and organoleptic characteristics during cold storage. For yogurt preparation, 25% liquid whey was substituted with the milk used for yogurt production, and after the fermentation process was complete, strawberry supplementation (12%). Results show that by using liquid whey in yogurt formulation, the syneresis index increased, whereas for texture properties, higher mean values of cohesiveness and springiness and lower values for hardness, adhesiveness, and gumminess were found. The time of storage also had a significant impact on the yogurt properties, and as the time of storage increased, the syneresis index increased and sensory scores reduced noticeably. The level of whey separation was significantly increased in yogurt samples containing liquid whey on the last day of storage, according to an evaluation of yogurt qualities (P<0.01). The results showed that although adding liquid whey into the yogurt production decreased the sensory characteristics (consistency and taste scores), yogurt with liquid whey and strawberry supplementation had an acceptable sensory score. Therefore, the use of liquid whey in the production of functional yogurt enables its reintroduction in the food supply chain and enhances sustainability.