Uilage is the empty space above the liquid in a wine bottle (or wine barrel or tank) usually after long storage. Ullage is used as an indicator of how well a cork seals its bottle. It is highly unusual for a wine bottle to retain its fill point without ullage after long storage since all corks tend to allow seepage to greater or lesser extent. In a very old wine, little or no ullage usually indicates that the wine has been stored under optimum conditions. Very large ullage in a bottle of table wine is a sure sign that the wine has been spoiled. (Wine/Service)