Barley contains high levels of phenolic compounds that provide health benefits, making it a valuable addition to diets. However, most studies focus on these compounds at full maturity, often neglecting their development during grain maturation, which is relevant for food quality. This study examines changes in phenolic content throughout grain development in four hull-less barley genotypes with different grain colors, developed specifically for food applications. The research aims to evaluate the phenolic profile and identify the optimal maturity stage for peak phenolic content and antioxidant capacity.