Does Aging Wine Increase Alcohol Content? Understanding

Does aging wine increase alcohol content? No. Aging wine does not increase its alcohol content. Scientific literature on wine conservation focuses on storage conditions and oxygen exposure. These affect a wine's sensory properties, chemical composition, and physical integrity over time. They do not affect its alcohol by volume (ABV). Wine can undergo significant chemical reactions during aging. Those reactions develop complexity and alter its flavor profile. They do not create additional alcohol. Instead, temperature, light, humidity, and the effectiveness of the bottle closure decide how a wine evolves. They also decide whether it deteriorates during long-term storage. For a deeper dive into common misconceptions about wine, explore our myth-bust with ABV data for the wines we cover.

What factors actually impact wine during aging?

When you hold fine wine for future enjoyment or resale, several factors shape its evolution. They are environmental and physical. The Australian Wine Research Institute (AWRI) highlights the conditions under which wine is stored and transported. Those conditions can have a major impact on its sensory properties once it reaches the consumer. This includes changes in yellow/brown color, acetaldehyde levels, and free and total SO2 levels, as noted by the AWRI. For red wines, chemical analysis includes spectral measurements for color and phenolics. Sensory analysis often reveals that wines exposed to extreme temperatures lose their fresh fruity characters. They show more developed fruit characters instead. At extreme levels they turn oxidised and cooked, according to the AWRI.

A study by Chanut et al. (2023) investigated the oxygen barrier properties of the bottleneck-stopper system. It ran over 24 months and simulated wine conservation. The research showed that model wine significantly increased total oxygen transfer at the glass-cork interface. That interface accounted for nearly 70% of the total oxygen transfer after three months of storage at 20°C. The study used a model wine solution with an ethanol concentration of 12.5% (v/v). It focused on oxygen transfer, not on changes in ethanol content. These findings underscore the interaction between the closure and the wine. Environmental factors mediate it, and it is crucial for a wine's long-term stability.

How does temperature affect wine aging and storage?

Temperature is one of the most critical factors influencing how wine ages. Excessive storage temperatures can have a marked effect on the shelf life of bottled wine. They lead to rapid aging and significant deterioration of the product, as stated by the AWRI. Marais (1986) observed the development of faulty flavors and decreasing overall quality after 12 months' storage of wine at 30°C. Temperatures exceeding 40°C can induce visual and sensory changes in a wine in only a matter of days, according to Ough (1986). The AWRI notes a threshold for storage places. Temperatures above 25°C for long periods and 40°C for short periods can affect wine quality, citing Ough (1992).

Thermal cycling, where temperature varies significantly, should be avoided, as Hirlam (2019a,b) observed. Such fluctuations can lead to leakage of wine or movement of cork stoppers, through thermal expansion. That affects appearance and marketability, even if not necessarily the wine's quality, according to the AWRI. Most experts, including Jancis Robinson, recommend constant temperatures between 10 and 15°C (50 and 59°F) for wine storage. Tom Stevenson suggests 11°C (52°F) may be ideal. Karen MacNeil recommends around 13°C (55°F) for wines intended for aging. We also state that wine can be stored at temperatures as high as 21°C (69°F) without long-term negative effects. Professor Cornelius Ough believes wine can be exposed to temperatures as high as 49°C (120°F) for a few hours without damage.

A study by Chanut et al. (2023) further detailed temperature's impact on oxygen transfer through microagglomerated corks.

Storage Condition (with model wine, horizontal)	Oxygen Diffusion Coefficient (D_stopper)	Total Oxygen Diffusion Coefficient (D_total)	Stability Period for D_total	Primary Impact on Oxygen Transfer
20°C	Unchanged over 24 months	Unchanged from 3 to 24 months	24 months	Sorption equilibrium of cork with water and ethanol reached within 3 months
35°C	Unchanged over 24 months	Similar to 20°C for up to 9 months	9 months	Sharp increase in D_total after 9 months, significant transfer at glass-cork interface
50°C	Unchanged over 24 months	Tremendous increase from 3 months	Less than 3 months	Leakage at glass-cork interface, possibly due to partial melting of surface treatment

Bottle shipping easily reaches 35°C. The Chanut et al. (2023) study found that at that temperature total oxygen transfer did not increase significantly for up to nine months. Beyond this, a significant transfer at the glass-cork interface started to occur. At 50°C, this shift occurred within the first three months of storage. It indicated leakage at the glass-cork interface, potentially from partial melting of the cork's surface treatment.

What role do light and humidity play in wine preservation?

Light exposure can significantly affect wine quality. It produces volatile sulfur compounds known as "lightstruck" flavor, according to the AWRI. This flavor comes from the formation of volatile sulfur compounds. Those compounds are believed to derive from sulfur-containing amino acids, as Maujean and Seguin (1983) demonstrated. Riboflavin (vitamin B2) undergoes photo-activation when exposed to light at wavelengths of 370 nm and 440 nm. That leads to the formation of these off-flavor compounds, as detailed in AWRI Technical Note TN09.

Dozon and Noble (1989) tested still and sparkling white wines in green glass. Those wines developed a statistically significant lightstruck flavor after 31.1 hours and 18 hours of exposure to fluorescent lamps, respectively. The same wines in clear glass developed this flavor after only 3.3 hours and 3.4 hours. Light-bodied white wines are most at risk. They are often packaged in tinted bottles for protection. Amber glass is most effective in excluding wavelengths below about 450 nm, according to Rankine (1989), cited by AWRI Technical Note TN09.

Humidity is also important, particularly for wines sealed with natural corks. If the air is too dry, corks can dry out, potentially leading to leakage, as the AWRI explains. A drying cork can allow oxygen to enter the bottle. The oxygen fills the ullage space and can make the wine spoil or oxidize. A figure of 75% humidity is often cited as ideal. Jancis Robinson notes there is little significant research to definitively establish an optimal range. Excessive humidity, however, can damage wine labels, hindering identification or hurting resale value. For guidance on assessing fill levels, refer to our guide on wine ullage levels explained.

Does bottle orientation matter for aging wine?

The orientation of a bottle during storage has been a subject of investigation. Some studies show little effect. Others suggest specific benefits. Mas et al. (2002) investigated the impacts of different alignments on bottles sealed with six different closures for a white and red wine. They found that, as a general rule, wines stored upright had higher yellow/brown color after 24 months than those stored horizontally. The differences were not significant. The study did show higher oxidation for upright samples sealed with agglomerated cork stoppers. Elevated acetaldehyde levels appeared in white wine samples from the three-month timepoint onwards, according to the AWRI. Another study by Skouroumounis et al. (2005) looked at Chardonnay and Riesling wines. It found that bottle orientation (horizontal or upright) had little effect on the chemical composition and sensory properties across a 60-month period.

For most wines, storing bottles on their side is a common practice. It is believed to keep the cork moist and prevent it from drying out. However, we also note research from the late 1990s. That work suggested a slight angle might be ideal. The angle lets the cork stay damp while keeping the ullage air bubble at the top, which may lead to slower, more gradual oxidation.

For Champagne and other sparkling wines, the Comité Champagne recommends storing bottles upright or on their sides. The place should be cool, at a constant temperature of between 10 and 15°C. Humidity should stay high and constant, between 60% and 80%. We also state that Champagne is often recommended to be stored upright rather than lying on its side. The internal pressure from trapped carbonic gas provides enough humidity and protection from oxygen. Caterer Magazine, cited, claims a finding from the Comité Interprofessionnel du Vin de Champagne (CIVC). Champagne stored on its side aged more quickly, through oxygen seepage after corks lost elasticity. However, the Comité Champagne's official website still recommends storing Champagne on its side, stating, "Champagne is ready for drinking upon release, matured to perfection in the producer’s cellars. It will, however, keep well for several years if stored on its side in a cool, dark, draft-free place, following the three golden rules of Champagne storage: Constant, low ambient temperature (around 10 °C/50 °F) Generous humidity No direct exposure to sunlight, noise or excessive vibration."

The Chanut et al. (2023) study used microagglomerated corks in model wine. It tested vertical storage, with the cork in contact with the vapor phase, and horizontal storage, with the cork in contact with the liquid phase. The storage position had no significant influence on oxygen transfer through the cork itself or at the glass-cork interface over a 24-month aging period at 20°C.

How do closures and interfaces influence oxygen transfer?

The type of closure used for a wine bottle plays a significant role in controlling oxygen ingress. That control is crucial for a wine's aging potential. Natural cork stoppers account for nearly half of the wine closure market, according to Chanut et al. (2023). The same authors note that a variety of stoppers are available. The list runs from cork-based, synthetic, and glass stoppers to screw caps. Each offers different oxygen barrier properties.

Oxygen does not transfer into a bottled wine through the stopper alone. A significant share passes at the interface between the cork stopper and the glass bottleneck. Chanut et al. (2023) highlighted that this glass-cork interface is a major pathway for oxygen entry. Their study used microagglomerated cork stoppers. It found that the oxygen diffusion coefficient of the cork wafer alone remained unchanged over 24 months. Storage conditions such as temperature, storage position, or the presence of model wine made no difference.

However, the presence of model wine significantly modified the total oxygen transfer. That total includes the transfer at the glass-cork interface. At 20°C, the total diffusion coefficient increased from 2.3 × 10−11 to 4.7 × 10−11 m2 s−1 after the initial three months of storage. The transfer at the glass-cork interface accounted for nearly 70% of the total oxygen transfer. This increase was attributed to the sorption of water and ethanol in the cork. That sorption can modify the cork's mechanical properties and favor surface diffusion.

High storage temperatures also have a strong impact on oxygen transfer at the interface. The Chanut et al. (2023) study observed that at 35°C, a significant increase in oxygen transfer at the glass-cork interface occurred after nine months of storage. At 50°C, this increase was noticeable within the first three months. The researchers described it as "leakage" at the interface. This could be due to a change in the mechanical properties of the stopper. It could also come from a partial melting of the paraffin and silicone coating applied to the cork's surface. These findings emphasize the importance of stable, cool storage conditions. They maintain the integrity of the bottleneck-stopper system and control oxygen exposure during aging. For more on proper storage, consult our guide on how to store wine.

Understanding these factors is crucial for managing your wine collection. You may be monitoring its condition for optimal drinking. You may be assessing its potential for future sale on the live fine wine market index.

To confidently decide when to drink or hold your wines, benefit from the 40/60 score on every wine. It gives you clear insight into peak potential.