High-protein fermented milk products such as Greek yogurt are conventionally produced by concentrating the coagulated milk after fermentation. This process generates acid whey that is undesired due to environmental concerns. An alternative approach to avoid acid whey is to concentrate the milk before fermentation by filtration or adding protein powders. However, resultant gels are firm so that stirring in the tank and further processing is difficult. It is also challenging to produce a smooth texture. In this study, yogurts from concentrate were manufactured and the effect of the final pH after fermentation on the physical properties was investigated. Additionally, the potential of power ultrasound (US) as a post-processing tool was examined. Skim milk was fortified with milk protein powder to 10% protein, heated (85°C, 30 min), and fermented with starter culture at 43°C. Fermentations were stopped at pH 5.0, 4.8, and 4.6, respectively, by breaking up the gel with a perforated disc and immersing the containers in iced water. Yogurts were sheared the next day through a nozzle (d = 3 mm) at a flow rate of 40 mL/s. Half of the samples were further treated with an US sonotrode for 10 s at a frequency of 20 kHz. Several physical properties were then analyzed (rheology, texture, particle size distribution, WHC). Additionally, the development of the gel firmness during acidification was monitored with a rheometer. Every 0.1 pH, a vane geometry was rotated in the milk/gel and the torque was recorded. The torque measured at pH 5.0, 4.8, and 4.6 was 4.2 ± 0.2, 4.8 ± 0.3, and 7.2 ± 0.3 Nm, respectively. The final pH after fermentation affected multiple physical properties of the final product. Yogurts fermented until pH 4.6 exhibited the highest apparent viscosity (2.18 ± 0.06 Pa·s). In contrast, when the acidification was already stopped at pH 4.8 and 5.0, the apparent viscosity was decreased by 36 and 40%, respectively. Moreover, the application of US as a post-process step further decreased the visual coarseness and viscosity, making it a beneficial tool to design high-protein products that meet ease of consumption.