A device to provide in-line flavor for water or other liquid stored in a container. An example device includes a body having a cylindrical shape chamber formed therein, and an opening on a first end of the body. A cartridge holder fits within the chamber of the body and retains a flavoring therein for the water or other liquid. The cartridge holder has a plurality of openings for the water or other liquid to flow through. When a user drinks from the drinking end, the water or other liquid flows from the container and through the housing and mixes with a flavoring from the cartridge holder before being drawn through to the drinking end so that the user drinks a flavored water or other liquid.