A bottle formed of a food-grade plastic material, such as clear polyethylene terephthalate includes a frustoconical neck portion, a shoulder region, a base region, and a sidewall portion have opposed grip-enhancing surfaces, and elastically deformable pressure panels. A cap for the container may include a valve to control product leakage, and may be sized to allow inversion of the bottle. A generally trapezoidal tab of the cap moves between a closed position covering a cap orifice and an open position outside the plane of the cap.