Automatic beverage mixer

A method for preparing a mixed beverage, the method comprising:

• obtaining a container comprising a sidewall, a first component, and an off-center opening disposed on a surface of the container, wherein the off-center opening is initially sealed, and wherein the off-center opening in the container is off-center with respect to the sidewall of the container;
• opening the container to expose the off-center opening;
• orienting a cap device having a chamber containing a second component to the container by rotating the cap device such that the exposed off-center opening of the container is aligned with a centering post extending from a bottom surface of the cap device, wherein the centering post is off-center with respect to a perimeter of the bottom surface of the cap device such that the centering post is placed directly over the off-center opening of the container when the cap device is oriented, and wherein the bottom surface of the cap device is configured to face the surface of the container comprising the off-center opening;
• snapping the cap device onto a rim of the container;
• moving a lock ring of the cap device after snapping the cap device onto the rim of the container;
• breaching a membrane of the cap device to release the second component into the container;
• and
• agitating the container and cap device to mix the first and second components together.