Why Old Wine Is Expensive: Understanding Value

Why old wine is expensive comes down to supply and demand. The surviving supply shrinks over time, while demand from collectors and connoisseurs remains strong for well-preserved bottles. The value of an older vintage hinges on two things: its condition, primarily indicated by its ullage level, and its provenance, or ownership history. Factors like consistent storage temperature, appropriate humidity, and protection from light and vibration are crucial for maintaining a wine's quality over decades. When these conditions are met, the wine can evolve positively, developing complex flavors and aromas. Poor storage, however, can lead to accelerated oxidation and faults, diminishing both drinkability and market value. For auction buyers, understanding these elements is essential to assess the true worth of a bottle.

What is ullage and why does it matter for old wine?

Ullage is the space between the wine and the top of the container, such as a bottle or barrel. It is also known as the fill level or headspace. This headspace is a mixture mostly of alcohol and water vapors with carbon dioxide that is a by-product of the fermentation process. In containers that are not completely air-tight, like a cork-stoppered wine bottle, oxygen can also seep into this space. Some oxygen is beneficial to the aging process of wine. Excessive amounts can lead to oxidation and other various wine faults.

As a wine ages in the bottle, the amount of ullage will continue to increase unless a wine is opened, topped up, and recorked. If the wine lies on its side, in contact with the cork, the cork will also absorb some of it. Longer corks have the potential to absorb more wine than shorter corks. Dirceu Vianna Junior MW, in a response in the August 2020 Decanter's Notes and Queries pages, stated that "aim for fill levels of 3-10mm at the time of bottling. Over time, some wine will be lost through cork absorption and evaporation." we also state that during the bottling process, most wineries strive for an initial ullage level of between 0.2-0.4 inches (5-10mm).

Generally, the greater the amount of ullage, the more potential that the wine has been exposed to harmful levels of oxidation. This is why auction houses and retailers of mature wines pay close attention to the ullage levels in determining the resale value of the wine. The ullage level can also give insight into the type of care and storage conditions that the wine was kept in. Matt Walls, DWWA regional chair for Rhône, told Decanter.com in 2018 that ullage is "the best guide you have to the condition of a bottle of wine, especially if you don't know for certain how it's been stored." Julia Sewell, sommelier at The Fat Duck and judge at DWWA, notes that "age aside, ullage lower than midshoulder level poses a much higher risk of spoilage," as reported by Decanter. You can learn more about specific fill levels and their implications in our guide to wine ullage levels explained.

How are ullage levels described for different bottle types?

Standard descriptions for fill levels differ for Bordeaux and Burgundy wines due to their distinct bottle shapes. WineBid trains its inspectors to document every possible bottle detail, including ullage.

Ullage Term	Bordeaux, Cabernet Sauvignon, and similar bottles
Base of neck or higher	No fill level is indicated. WineBid considers anything in the neck a perfect fill level for any bottle of any age.
Very top shoulder	Indicates a slightly low fill at bottling and/or a slight natural reduction through cork and capsule. An excellent fill level for any wine more than 20 years old.
Top shoulder	On the high slope of the shoulder. Acceptable and normal for wines 15 years of age and older, and very good for wines 35 years of age and older.
Mid shoulder	Suggests ullage dropped during the life of the wine through easing of the cork and/or inconsistent storage. May be normal for a wine 40 years old or older.
Low shoulder	Occurs in older wines.

For Burgundy, Pinot Noir and wines in similar bottles, WineBid measures fill in centimetres between cork and wine instead, because those bottles are shaped differently.