The purpose of the current study was to produce a blackthorn-based beverage with improved nutritional value. In this regard, several beverages were formulated using sugar and citric acid. Then, the effects of the different food constituents on the in vitro recovery and antioxidant capacity of the bioactive substances in the formulations were determined. Based on the results, the addition of citric acid or sugar increased the phenolic extractability (297.0 and 299.2 mg gallic acid equivalent (GAE)/100 g in blackthorn + citric acid (BC) and blackthorn + sugar (BS), respectively) and antioxidant capacity (750.8 and 821.8 mg trolox equivalent (TE)/100 g in the BC and BS, respectively), when compared with that of the control beverage (224.4 mg GAE/100 g and 515.5 mg TE/100 g in B; without citric acid and sugar). These outcomes were in line with the results of the simulated in vitro digestion, wherein the addition of sugar resulted in a higher recovery of total phenolics (91.74%). Moreover, according to the chromatographic evaluations, gallic acid, protocatechuic acid, chlorogenic acid, ferulic acid, quercetin-3-O-glucoside, quercetin, kaempferol, cyanidin-3-O-glucoside, and peonidin-3-O-glucoside also confirmed these results. It can be concluded that blackthorn is a good and cheap candidate for beverage formulations due to it having a high quantity of various types of phenolic compounds as well as their antioxidant potentials. Aside from its phenolic characterization, the comparatively high digestive stability of phenolic antioxidants makes this fruit a potential alternative for beverage production.