Branched-chain amino acids (BCAAs), leucine, isoleucine, and valine, are essential amino acids important for muscle metabolism, recovery, and energy regulation. However, their inherently low solubility and bitterness limit their use in functional foods and nutritional formulations. This study presents a combined pH-shifting and high-pressure processing (HPP) strategy to encapsulate BCAAs within dairy protein matrices to improve their solubility and sensory performance. Leucine was selected as the model amino acid due to its strong bitterness and its central role in stimulating muscle protein synthesis. pH shifting increased leucine solubility, reaching 4 w/v% at neutral pH and up to 8 w/v% at alkaline pH (pH 11). Then, HPP was used to engineer whey-protein–based encapsulation matrices. At high whey protein isolate (WPI) concentrations (16% WPI) and 8% leucine, HPP induced protein gelation that effectively entrapped leucine within a three dimensional network. At lower protein concentrations (4% WPI) and 4% leucine, HPP promoted partial protein unfolding and hydrophobic interactions that facilitated leucine encapsulation. Overall, alkaline pH conditions enhanced encapsulation efficiency compared with neutral pH, and higher pressure (600 MPa) showed significantly stronger encapsulation than lower pressure (300 MPa). These findings show a robust, scalable approach for improving the functional and sensory properties of BCAAs in high-protein food systems.