High-power ultrasound has recently been approved for the treatment of crushed grapes; it can be considered as a highly promising technology that can be adopted for several purposes in the winemaking process. The effect of ultrasound used at different amplitudes (30, 60, and 90%) and over different periods of time (2, 6, and 10 min) on the main polyphenols and other analytical indices relating to the sensory properties of red wines was studied. An increase in the amplitude and sonication time did not affect the initial polyphenol profile, and no degradative phenomena were revealed. A significant increase in the HCl index and a decrease in the astringency index and particle size were highlighted in all sonicated samples. The significant effects of ultrasounds were described well by the power law function, logistic, and Peleg's model, with good fitting results obtained (R2 > 0.94). Some scale-up considerations were reported with regard to the acoustic energy density (AED), as an intensive parameter of ultrasound treatments.