the.com/ullage
the empty space wine leaves behind, measured like a confession of what's missing
barrel breathEvaporation through wood is called the angel's share
fill it upTopping off the gap prevents oxidation and spoilage
rocket fuelSpacecraft tanks need ullage settling before engines fire
old rootsComes from Latin oculus, the eye, meaning the bunghole
auction tellHigh ullage signals an old bottle may be ruined