Is Old Wine Safe to Drink? Understanding Quality

Is old wine safe to drink? In most cases yes, but its quality and enjoyment can degrade significantly over time. While most "bad" wine is unpleasant rather than harmful, specific faults can render a bottle undrinkable. The primary concern with older vintages is oxidation. This occurs when wine is exposed to too much oxygen, often indicated by a low fill level, known as ullage. Factors like storage conditions, cork integrity, and the wine's intrinsic composition all play a role in how well it ages. Assessing these elements before opening an old bottle helps you anticipate its condition and avoid disappointment. That protects both your palate and your investment in fine wine.

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

Ullage, also called fill level or headspace, is the space between the wine and the bottom of the cork in a bottle. It is one of the most important indicators of a mature wine's condition, particularly for auction houses and retailers. As wine ages, some liquid is lost through cork absorption and evaporation. That process is sometimes referred to as the "angel's share" in barrels. The greater the amount of ullage, the more potential the wine has been exposed to harmful levels of oxidation.

What do wine experts say about fill levels?

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." 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." David Dudley-Jones of Dudley Jones Fine Wines noted in Decanter magazine 2016 that "lower fill levels [in the bottle neck] and resultant seepage usually point to heat exposure and poor storage." WineBid note that fill level descriptions vary for Bordeaux and Burgundy wines, because the two bottle shapes differ.

Bordeaux and Cabernet Sauvignon Bottles

For Bordeaux, Cabernet Sauvignon, and wines in similar bottles, WineBid uses specific ullage terms:

• Base of neck or higher: Considered a perfect fill level for any bottle of any age. If no fill level is indicated by WineBid, it means it is at the base of the neck or higher.
• Very top shoulder: An excellent fill level for any wine more than 20 years old, indicating a slight natural reduction.
• Top shoulder: An acceptable and normal fill level for wines 15 years of age and older, and a very good fill level for wines 35 years of age and older. Christie's guidance published in 2013 also states that "Top shoulder" is normal for any claret 15 years or older, according to Decanter.
• Mid shoulder: May be normal for a wine that is 40 years old or older. It suggests ullage has dropped due to easing of the cork or inconsistent storage conditions, WineBid states. Christie's also says "mid-shoulder" is not abnormal for a 30 to 40-year-old wine, Decanter reports.
• Low shoulder: Occurs in older wines, according to WineBid. Christie's considers a bottle of Bordeaux with ullage down at the "low shoulder" as "and usually only accepted for sale if wine or label exceptionally rare or interesting'," Decanter notes.

Michael Broadbent, Master of Wine and senior consultant of Christie's auction, developed a guide for evaluating ullage levels of matured wines in the late 1980s. It focuses primarily on Bordeaux and has been widely accepted.

Ullage Level (in/cm)	Appearance	Assessment
0.12 in (0.3 cm)	High up to the cork	Normal level for young wines
0.2 in (0.5 cm)	High in neck	Good condition for any age
0.6 in (1.5 cm)	Top of the shoulders	Normal for older wines. Good condition for wines over 15 years
1 in (2.5 cm)	Upper part of shoulders	Generally okay in older wines, especially those over 20 years
1.18-1.38 in (3-3.5 cm)	Mid to mid-low shoulders	Possible oxidation. Price should reflect the risk.
2.36-2.75 in (6-7 cm)	Low shoulders to below shoulders	Extremely risky. Possibly undrinkable

Burgundy and Pinot Noir Bottles

Burgundy ullage is historically measured in centimeters because Burgundy bottles are shaped differently, WineBid explains. Fill levels are measured by looking at the space between the cork and wine. Christie's states that "condition and drinkability of Burgundy is less affected by ullage than its equivalent from Bordeaux," according to Decanter. Christie's also treats ullage of up to 7cm as relatively normal in 30-year-old Burgundy.

WineBid's Burgundy ullage terms:

• Two centimeters or less: Considered an excellent fill for any age and does not need to be mentioned.
• Three centimeters: A perfectly normal fill for wines 12 years and older, and an excellent fill level for wines 25 years or older.
• Four centimeters: Considered a normal fill for wines more than 20 years old and excellent for wines more than 35 years old.
• Five centimeters: Not uncommon in wines 30 years old or older.

You can use our ullage band to drinkability for 30 to 50 year old bottles to cross-reference your cellar's condition data.

How do storage conditions affect wine aging and ullage?

Proper storage conditions are crucial for minimizing ullage and preserving wine quality. Wines kept at ambient humidity levels and in temperatures between 50-59 °F (10-15 °C) will experience evaporation and diffusion at a slower rate than wine kept in lesser conditions. They therefore show lower ullage levels. Decanter notes that long-term storage requires a temperature of around 13°-15°C and a humidity level of 70% or so, along with an absence of light and vibration. Abnormally low fill levels indicate poor storage conditions, namely high temperature or low humidity, according to Dirceu Vianna Junior MW, as reported by Decanter.

How does the cork itself let oxygen into the bottle?

Chanut et al. published a study in PNAS Nexus in 2023. It investigated the oxygen barrier properties of the bottleneck-stopper system using microagglomerated corks and model wine over 24 months. The study found that the oxygen diffusion coefficient of the cork stopper alone was not modified regardless of the storage conditions, including temperature, storage position, or the presence of model wine. However, the total oxygen transfer, which includes transfer at the glass-cork interface, was affected by the presence of model wine. The total diffusion coefficient increased from 2.3 × 10 −11 to 4.7 × 10 −11 m 2 s −1 after the initial three months of storage at 20°C. Transfer at the glass-cork interface accounted for nearly 70% of the total oxygen transfer.

The Chanut et al. study also found that the storage position (vertical or horizontal) did not significantly influence oxygen transfer through the bottleneck-cork system. However, temperature had a strong impact. At 20°C, oxygen barrier properties remained unchanged over 24 months. At 35°C, a temperature easily reached during bottle shipping, total oxygen transfer did not increase significantly for up to 9 months. Beyond this duration, a significant transfer at the glass-cork interface began to occur. At 50°C, this shift occurred within the first 3 months of storage. Total diffusion coefficients reached values approaching that of oxygen in the air, indicating leakage at the glass-cork interface, according to Chanut et al. This could be due to a partial melting of the paraffin and silicone surface treatment on the cork stopper. Understanding these dynamics can help you make informed decisions about your fine wine investment and how to store wine in your cellar.

What wine faults can affect drinkability in old wines?

While old wine is generally not unsafe in a toxicological sense, various wine faults and taints can make it undrinkable. The Australian Wine Research Institute (AWRI) details several common issues:

• Oxidation: This is a common fault, particularly in white wines. It can lead to sensory characteristics ranging from a dulling of the aroma to "cardboard," "straw," "hay-like," "sherry-like," and "madeirised" aromas. In extreme cases, "wet wool," "wet dog," or "varnish-like" aromas can be evident, AWRI states. Acetaldehyde increases as wines age due to chemical oxidation of ethanol, according to AWRI. It can impart "over-ripe bruised apples" or "sherry" and "nut-like" characters above 125 mg/L.
• Volatile Acidity (VA): Often perceived as the odor of vinegar, volatile acidity comes primarily from acetic acid. While small amounts are produced during fermentation, increased levels in stored wines are usually due to the growth of acetic acid bacteria in the presence of oxygen, AWRI notes. The aroma threshold for acetic acid is as low as 0.1-0.125 g/L, but it is usually considered detrimental above 0.7 g/L, AWRI reports.
• Ethyl Acetate: This ester can contribute to the sensory perception of volatile acidity. It is perceived as the odor of nail polish remover, with a sensory threshold of 12 mg/L, according to AWRI. While low levels can add "fruity" aroma, concentrations of 150-200 mg/L are considered defective.
• Mousiness: This off-flavor is reminiscent of caged mice or cracker biscuit. It is generally perceived late on the palate or after swallowing, rendering the wine undrinkable for sensitive individuals, AWRI explains. It is usually of microbial origin, often from lactic acid bacteria, and is more likely to occur in wines with low concentrations of SO2 and low acidity.
• Reductive Faults: A range of volatile sulfur compounds can form, leading to "rotten egg gas" (hydrogen sulfide), "cabbage," "garlic," "onion," or "rubber" aromas (sulfhydryls), and "onions," "cooked cabbage," "burnt rubber," or "garlic" (disulfides), AWRI details. Dimethyl sulfide (DMS) can also form during bottle maturation, contributing "vegy" or "blackcurrant" at low concentrations, but "asparagus," "cooked corn," "cooked tomato," or "molasses" at higher concentrations, AWRI states.
• Cork Taint (TCA and TBA): The main compound responsible for cork taint is 2,4,6-trichloroanisole (TCA), which has a distinct musty, mouldy aroma. One study determined its aroma threshold in Pinot Noir wine as 1.4 ng/L. It can be lower in dry white wines or higher in full-bodied reds, AWRI reports. 2,4,6-tribromoanisole (TBA) also causes similar musty, mouldy aromas and is perceptible at 4 ng/L in wine, according to AWRI. These taints can arise from moulds on cork or even from oak without cork contact.

These faults highlight why careful assessment of condition is vital for older wines. You can explore wine ullage levels explained for more detailed information on condition assessment.

How can you tell if an old wine is bad before opening?

While tasting is the ultimate test, several visual and tactile clues can help you anticipate the condition of an old bottle. Matt Walls, speaking to Decanter, suggests that if the fill level is much below the bottom of the neck of a Bordeaux bottle, you should "think twice before buying it." He also notes that Burgundy bottles are harder to gauge due to their tapering shape.

Julia Sewell, sommelier at The Fat Duck, told Decanter that "age aside, ullage lower than midshoulder level poses a much higher risk of spoilage." She also advises that "ullage level can give you a few clues about your wine before you have the opportunity to open the bottle."

What checks can you make before pulling the cork?

To get an indication of a wine's condition without pulling the cork, Dirceu Vianna Junior MW recommends the following, as reported by Decanter:

• Shine a strong light at the punt to get clues about the level of sediment and abnormal loss of color.
• Cut the capsule to inspect the condition of the cork and check for signs of seepage.
• Gently touch the cork to ensure it does not move.

However, Matt Walls cautions that ullage is "not a totally reliable measure of condition however; you do sometimes come across old bottles with a very low fill that have remained in good nick." Julia Sewell adds that "most aspects of a wine, the clues can only be confirmed once the wine is tasted, but it's certainly a help in anticipating the condition." The best advice for buyers is always to try to establish the provenance of the bottle to minimize risks, according to Junior, as reported by Decanter.

For those considering how to buy wine at auction, these checks are particularly important for evaluating potential purchases.

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