A container includes a receptacle to hold nutrients and other food contents for a smoothie. The container is used with a larger vessel such as a blender into which the capsule is inserted and into which water or other fluid is poured. When the blender is closed, the container opens to release its contents for blending with the fluid into a delicious, healthful smoothie. The container may have a cover with opening flaps and relatively movable elements that pivot the flaps open when opposite forces are applied to the container by the larger vessel.