Ullage

Look at a wine that was bottled a few years ago. You’ll see that the liquid nearly reaches the cork. Now look at a wine bottled a few decades ago. The liquid is somewhere around the shoulder of the bottle. That space between liquid and cork is called ‘ullage’. As wine evaporates over time, the ullage increases, allowing more oxygen to come into contact with the wine. For some wines, like great Barolo, that’s all part of the plan. For others, though, that exposure can ruin the wine, meaning bottles with substantial ullage should give you reason for pause. It’s also worth noting that improper storage conditions, like exposure to sunlight and heat, will cause greater ullage, so you should only buy these wines from trusted sources.