An apparatus for mixing a concentrated product and a liquid, comprising: a body defining an internal volume ; and a mixing device positioned at least partially within the internal volume , wherein the mixing device comprises one or more vanes that separate the internal volume into a first portion and a second portion when the mixing device is in a first position, and wherein the first portion and the second portion are in fluid communication with one another when the mixing device is in a second position; wherein the one or more vanes are configured to be rotated about a shaft of the mixing device to move the mixing device from the first position to the second position, and wherein the one or more vanes are positioned radially-outward from the shaft ; wherein the mixing device further comprises a guide that at least partially surrounds the shaft ; characterized in that - either the one or more vanes define a notch or slot, and wherein the guide is positioned within the notch or slot such that an outer radial surface of the guide is substantially flush with outer radial surfaces of the one or more vanes , - or an outer radial surface of the guide is radially-outside of the outer radial surfaces of the one or more vanes , and wherein the guide is at least partially received in a recess in an inner surface of the body . a body defining an internal volume ; and a mixing device positioned at least partially within the internal volume , wherein the mixing device comprises one or more vanes that separate the internal volume into a first portion and a second portion when the mixing device is in a first position, and wherein the first portion and the second portion are in fluid communication with one another when the mixing device is in a second position; wherein the one or more vanes are configured to be rotated about a shaft of the mixing device to move the mixing device from the first position to the second position, and wherein the one or more vanes are positioned radially-outward from the shaft ; wherein the mixing device further comprises a guide that at least partially surrounds the shaft ; characterized in that - either the one or more vanes define a notch or slot, and wherein the guide is positioned within the notch or slot such that an outer radial surface of the guide is substantially flush with outer radial surfaces of the one or more vanes , - or an outer radial surface of the guide is radially-outside of the outer radial surfaces of the one or more vanes , and wherein the guide is at least partially received in a recess in an inner surface of the body . - either the one or more vanes define a notch or slot, and wherein the guide is positioned within the notch or slot such that an outer radial surface of the guide is substantially flush with outer radial surfaces of the one or more vanes , - or an outer radial surface of the guide is radially-outside of the outer radial surfaces of the one or more vanes , and wherein the guide is at least partially received in a recess in an inner surface of the body . - or an outer radial surface of the guide is radially-outside of the outer radial surfaces of the one or more vanes , and wherein the <EOS>