A flavor infusing system which allows for a flavor concentrate to be dispensed into a fluid upon demand for fluid through a straw. Specifically, the systems and methods allow for a flavor concentrate to be mixed into fluid within a straw as the fluid is drawn through the straw via sucking on the straw at a variable ratios. The system may comprise a stand-alone straw useable with any source of base fluid, or may be incorporated into a cover or similar component of a water bottle, flask, or mug to provide for an integrated unit.