Apparatus and method for protecting stored wine against exposure to air

An apparatus for protecting against oxidation wine stored in a container having an open mouth and determined by a generally cylindrical wall with an interior surface, and a bottom having an outlet, comprising:

• a generally cylindrical piston determined by generally parallel, generally circular upper and lower faces, and a peripheral surface generally orthogonal to the faces and circumscribed by an O-ring assembly having upper and lower O-rings in slidable contact with the interior surface of the container wall;
• a rod generally orthogonal to the piston faces and having a generally circular cross-section of a preselected diameter and a lower end attached to the piston upper face;
• a generally cylindrical weight having a bore therethrough which closely receives the rod, the weight contacting the piston upper face;
• and
• a valve generally orthogonal to the piston faces and extending through the piston, the valve having a lower end proximate to the piston lower face.

A method for protecting against oxidation wine stored in a container having an open mouth and determined by a wall with an interior surface, and a bottom having an outlet, comprising the steps of:

• covering the container mouth with a weight-activated piston in slidable contact with said interior surface;
• removing air displaced from the container when the piston initially moves downward until it contacts the wine surface;
• and
• maintaining contact between the piston and wine surface, and removing air displaced thereby, as the volume of wine gradually decreases.