Sediment in Old Wine Explained: What It Means for Your
Updated
Want sediment in old wine explained? Start with what the bottle shows you before the cork comes out. When evaluating an older bottle of wine, examining the level of sediment can offer clues about its condition without opening it. Dirceu Vianna Junior MW suggests one check in Decanter. Buyers can shine a strong light at the punt to get clues about the level of sediment and abnormal loss of colour. Sediment, as a physical deposit, provides insights into a wine's history and potential for enjoyment when assessed alongside other visual cues like ullage. Assessing sediment is a step in evaluating a bottle's health, particularly for older vintages. It does not detail specific sediment types or their direct implications for drinkability. Instead, the available information primarily focuses on ullage, the air gap in the bottle, as a more direct indicator of oxygen exposure and storage conditions.
What is ullage and why does it matter for your wine?
Ullage, also known as the fill level or headspace, is the gap between the cork in the bottle and the wine itself, as Decanter explains. WineBid defines ullage as "the space at the top of the wine bottle not occupied by wine." Most wineries aim for initial fill levels of 3-10mm at the time of bottling, according to Dirceu Vianna Junior MW in Decanter. A range of between 0.2-0.4 inches (5-10mm). Over time, some wine is lost through cork absorption and evaporation because a cork is not a completely airtight sealant. As a wine ages in the bottle, the amount of ullage will continue to increase unless a wine is opened, topped up, and recorked.
The headspace of air in a bottle is a mixture mostly of alcohol and water vapors with carbon dioxide. That carbon dioxide is a by-product of the fermentation process. In containers that are not completely air-tight, oxygen can also seep into this space. While some oxygen is beneficial to the aging process of wine, excessive amounts can lead to oxidation and other various wine faults. A low ullage can indicate seepage and oxidation of the wine, and affect its value considerably, according to WineBid. The ullage level can also give insight into the type of care and storage conditions the wine was kept in. 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. For more details on fill levels and their implications, see our guide on wine ullage levels explained.
How do auction houses assess ullage levels?
Auction houses and retailers of mature wines pay close attention to ullage levels when determining the resale value of wine. Buyers for auction houses, for example, will pay close attention to ullage as part of their assessment of the wine's health, Decanter reports. 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 stated in Decanter magazine in 2016 that buyers "must look at it as a marker of how well the wine's been stored, as lower fill levels [in the bottle neck] and resultant seepage usually point to heat exposure and poor storage." Julia Sewell, sommelier at The Fat Duck, notes in Decanter that it "is often the age of the wine that will determine whether ullage is of concern," as a bottle naturally evaporates very slowly through the permeable cork.
Wine merchants and auction houses use standard descriptions for fill levels. These descriptions differ for Bordeaux and Burgundy wines due to their distinct bottle shapes. Michael Broadbent, a 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 focused primarily on Bordeaux. This guide has been generally accepted and widely used in the wine market as an evaluation tool for all sorts of wine.
Here are common ullage terms for Bordeaux and similar bottles, as described by WineBid:
| Ullage Level | Assessment |
|---|---|
| Base of neck or higher | Perfect fill level for any bottle of any age |
| Very top shoulder | Excellent fill level for any wine more than 20 years old |
| Top shoulder | Acceptable and normal fill level for wines 15 years of age and older. It is a very good fill level for wines 35 years of age and older |
| Mid shoulder | May be normal for a wine that is 40 years old or older |
| Low shoulder | Occurs in older wines |
Michael Broadbent's guide, offers a more precise measurement:
| 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 |
For Burgundy, Pinot Noir, and wines in similar bottles, WineBid provides these ullage terms:
| Ullage Level | Assessment |
|---|---|
| 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. It is 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 |
Matt Walls advises in Decanter that if "the fill level is much below the bottom of the neck of a Bordeaux bottle, I'd think twice before buying it." He also notes that "Burgundy bottles are a little harder to gauge due to their gradually tapering shape." When buying an expensive older bottle, Walls suggests lining up available bottles and choosing the one with the highest fill, "just to be safe." However, he cautions that this is "not a totally reliable measure of condition." For more on buying, see our guide to buying wine at auction.
Does bottle storage position affect oxygen transfer?
A bottle can be stored vertically or horizontally. Neither position significantly influences oxygen transfer through microagglomerated corks or at the glass-cork interface, according to a 2023 study by Chanut et al. The study investigated the oxygen barrier properties of microagglomerated cork stoppers (Diam 5 type) in contact with model wine over 24 months. It found that the values of the total oxygen diffusion coefficient for vertical and horizontal storage were similar on average. Chanut et al. (2023) note that the literature on bottle storage position is not settled. Some studies show no significant effect on oxygen transfer, while others suggest a slowing of oxidation in horizontal storage. The Chanut et al. study specifically found that after 3 months of storage at 20°C, the presence of model wine favored oxygen transfer at the glass-cork interface. The storage position itself had no significant influence on this transfer for all durations measured (3 to 24 months). This suggests that for microagglomerated corks, keeping the cork moist by horizontal storage may not be as critical for oxygen ingress as previously thought. You can learn more about optimal conditions in our guide on how to store wine.
How does storage temperature affect oxygen transfer and cork integrity?
Storage temperature has a strong impact on oxygen transfer through the bottleneck-cork system, particularly at the glass-cork interface. Chanut et al. (2023) demonstrated this in their study on microagglomerated corks and model wine. At a storage temperature of 20°C, the oxygen barrier properties of the cork stopper alone remained unchanged over 24 months of aging. However, the total oxygen transfer includes transfer at the glass-cork interface, and it increased significantly after the first 3 months of storage at 20°C. That interface accounted for nearly 70% of the total oxygen transfer, Chanut et al. (2023) found.
At higher temperatures, the impact becomes more pronounced:
- 35°C: Total oxygen transfer did not increase significantly for up to 9 months. Beyond this duration, a significant transfer at the glass-cork interface started to occur, according to Chanut et al. (2023).
- 50°C: A tremendous oxygen transfer occurring at the glass-cork interface was noticeable even from 3 months of storage. This phenomenon was further accentuated after 6 months, reaching a value approaching the diffusion coefficient of oxygen in the air. That indicated the presence of leakage at the glass-cork interface, Chanut et al. (2023) reported.
This increased oxygen transfer at higher temperatures could be attributed to a partial melting of the surface treatment agent. That agent, composed of paraffin and silicone, is applied to the external surface of the cork stopper. Another explanation is a modification of the mechanical properties of the stopper, Chanut et al. (2023) suggest. For instance, at 35°C, the liquid:solid ratio of the coated product increased to 19%, and at 50°C it reached 41%. That change potentially favors oxygen transfer at the interface, Chanut et al. (2023) explain.
What are common wine faults related to oxygen exposure?
Excessive oxygen exposure can lead to various wine faults that diminish a wine's quality and value. Low ullage levels or compromised cork integrity often signal that exposure. The Australian Wine Research Institute (AWRI) details several such faults:
- Oxidation: Particularly common in white wines, oxidation can lead to a dulling of the aroma and sensory characteristics described as 'cardboard', 'straw', 'hay-like', 'sherry-like', or 'madeirised'. In extreme cases, 'wet wool', 'wet dog', or 'varnish-like' aromas can be evident, AWRI reports.
- Acetaldehyde: This compound can impart odours described as 'over-ripe bruised apples', 'stuck ferment' character, or 'sherry' and 'nut-like' characters, AWRI states. The sensory threshold for acetaldehyde ranges from 100-125 mg/L, according to AWRI.
- Volatile Acidity (VA): VA is generally perceived as the odour of 'vinegar'. It has a reported aroma threshold in wine as low as 0.1-0.125 g/L, depending on the wine style and individual, AWRI notes. The legal maximum content of volatile acidity in Australian wines, excluding SO2 and expressed as acetic acid, is 1.5 g/L, AWRI reports.
- Ethyl Acetate: This fault is perceived as the odour of 'nail polish remover' and has a reported sensory threshold of 12 mg/L, AWRI states. At low levels, it can contribute 'fruity' aroma properties, but at higher concentrations (above 150-200 mg/L), it indicates a defective wine, AWRI explains.
- Mousiness: This off-flavour is reminiscent of 'caged mice' or 'cracker biscuit'. It is generally perceived late on the palate or after the wine has been swallowed, AWRI describes. The compounds responsible, such as 2-acetyltetrahydropyridine (ACTPY), are not volatile at wine pH, making them rarely detected by sniffing, AWRI notes. Mousy taint is more likely to occur in wines with low concentrations of SO2 and low acidity, AWRI reports.
Understanding these potential faults is crucial for assessing the long-term viability and investment potential of your collection. For insights into how these factors can influence value, explore our fine wine investment guides.
When you are evaluating your collection, whether for drinking now or for sale, understanding the condition of your bottles is paramount. Sediment and ullage levels offer key insights into a wine's journey and its potential. To stay informed on market trends and make data-driven decisions about your holdings, monitor the live fine wine market index.