Techniques are described to increase product viscosity in fiber-containing food slurries having a given amount of food solids. The techniques employ one or more PSR operations as the last unit operation prior to filling to reduce particle size within the food slurry and increase product viscosity. In one or more implementations, the PSR operation may comprise an aseptic cold PSR operation such as aseptic cold homogenization. In embodiments, the PSR operation may further be controlled to reduce variability in the viscosity of the finished product.