Just the Cork

• When you open up a bottle of riesling, oxygen from the air immediately enters. Once this happens, physical and chemical deterioration begins. This oxygen doesn’t exit when you re-cork the bottle and set it on the counter for next time. Instead, the oxygen will encourage the growth of Acetobacter bacteria, which eventually turn the bottle to vinegar. A partially consumed, re-corked bottle of riesling only lasts about two days at room temperature, five days in the refrigerator.

Oxygen Out

• Pour the contents of a partially consumed bottle of riesling into a clean bottle that is half the size with a tight fitting lid. This trick leaves less room for oxygen, doubling the amount of time the riesling keeps without deteriorating. Another option is preserving the leftover wine by injecting the bottle with a nitrogen, carbon dioxide and argon blend. This blend of flavorless, colorless and odorless gasses, creates a barrier between the wine and any oxygen in the bottle, slowing oxidation.

Preserved in the Fridge

• After injecting a bottle of riesling with the wine preservation spray, seal it with the original cork or insert a replacement stopper. Refrigerate the bottle immediately and store it upright until the next time you plan to serve it. The cool temperatures of the refrigerator slow the oxidation that leads to deterioration, preserving the taste and texture for approximately three weeks.

Oxidation Clues

• Discard riesling once it begins to show signs of deterioration. A smell of vinegar or nail polish remover when you remove the cork is a clue that the wine has seen its day. Once riesling begins to experience the effects of oxygen in the bottle, you may also notice dullness in color. In some cases, riesling that was once a pale yellow in color turns dark or even brown.