Does Wine Keep Aging in a Bottle? Conditions for Longevity

Does wine keep aging in a bottle? Yes, it does. Its evolution and longevity depend heavily on the conditions under which it is stored. Most wine is consumed within 24 hours of purchase. Fine wines often go into long-term storage instead. There they can improve in flavor and value with age, or rapidly deteriorate if conditions are inadequate. The Australian Wine Research Institute (AWRI) recommends that bottled wine be stored with the cork in contact with the wine. The location should be cool (15-20°C) and dry, according to Amon and Simpson (1986). Critical factors include temperature, humidity, light exposure, bottle orientation, and vibration. All of them significantly impact a wine's sensory properties and chemical composition over time.

How does oxygen affect wine aging in the bottle?

Oxygen ingress is crucial for wine's evolution, but excessive exposure can lead to spoilage. Controlled low oxygen intakes are usually required for wine to evolve. They let it reach its optimal organoleptic characteristics, as Karbowiak et al. (2010) state, cited by Chanut et al. (2023). The glass-cork interface is a major pathway for oxygen entry into bottled wines. A study by Chanut et al. (2023) demonstrated that this interface accounts for nearly 75% of total oxygen transfer. That figure came from miniaturized bottle systems with microagglomerated corks and model wine at 20°C.

The oxygen diffusion coefficient of the cork stopper alone was not modified by the storage conditions. Temperature, storage position, and the presence of model wine made no difference, even after 24 months of storage in the Chanut et al. (2023) study. However, the presence of model wine modified the total oxygen transfer. That total includes the transfer through the stopper and at the glass-cork interface. Chanut et al. (2023) observed that 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 at 20°C. This increase is attributed to the sorption of water and ethanol in the cork. That sorption can affect the cork's mechanical properties and promote oxygen transfer at the glass-cork interface. The sorption equilibrium of cork with water and ethanol was reached within the first three months. After that, the barrier properties of the bottleneck-cork system did not change, according to Chanut et al. (2023). Understanding these dynamics helps you anticipate the plateau and decline phases in our drink-window curves for your own collection.

What role does temperature play in wine aging?

Temperature is a critical factor in how wine ages. Higher temperatures accelerate chemical reactions and can lead to spoilage. Excessive storage temperatures will have a marked effect on the shelf life of bottled wine, according to AWRI Technical Note TN09. Marais (1986) observed the development of faulty flavors and decreasing overall quality. That came after 12 months’ storage of wine at 30°C, as cited by AWRI Technical Note TN09. Temperatures in excess of 40°C will induce visual and sensory changes to a wine in only a matter of days (Ough 1986, cited by AWRI Technical Note TN09). In general, temperatures above 25°C for long periods can affect wine quality. So can 40°C for short periods (Ough 1992, cited by AWRI Technical Note TN09).

The rate of chemical reactions in wine doubles with each 18°F (10°C) increase in temperature. Lower temperatures therefore let wine develop more slowly. Most experts, such as Jancis Robinson, recommend that wine be kept at constant temperatures between 50 and 59°F (10 and 15°C). Tom Stevenson speculates that 52°F (11°C) may be the most ideal temperature for storage and aging. Karen MacNeil recommends keeping wine intended for aging in a cool area with a constant temperature around 55°F (13°C). Professor Cornelius Ough of the University of California, Davis, believes wine can take temperatures as high as 120°F (49°C) for a few hours. It will not be damaged.

Thermal cycling, where the temperature varies significantly, should be avoided, as Hirlam (2019a,b) observed. Exposure to temperatures significantly greater than ambient can cause leakage of wine or movement of cork stoppers, through thermal expansion. That affects appearance and marketability. Quality is not necessarily implied to be affected, states the AWRI.

Chanut et al. (2023) further investigated the effect of storage temperature on oxygen transfer in miniaturized bottle systems with model wine. At 20°C, the oxygen barrier properties remained unchanged over 24 months. Bottle shipping easily reaches 35°C. At that temperature, total oxygen transfer did not increase significantly for up to 9 months. Beyond that duration, a significant transfer at the glass-cork interface started to occur. At 50°C, this shift occurred within the first 3 months of storage, indicating leakage at the glass-cork interface. This phenomenon could be attributed to a partial melting of the paraffin and silicone surface treatment agent on the cork stopper. A modification of the stopper's mechanical properties could also play a part, according to Chanut et al. (2023). These temperature effects can impact the long-term value of your collection, which you can track on the live fine wine market index.

How do light and humidity impact wine in the bottle?

Both light and humidity are crucial environmental factors that significantly influence wine quality during storage.

Light Direct sunlight or incandescent light can adversely react with phenolic compounds in wine and create "wine faults." Light exposure can affect the taste of a wine. It produces volatile sulfur compounds, known as ‘lightstruck’ flavour, according to the AWRI. Maujean and Seguin (1983) demonstrated that ‘lightstruck’ flavour is due to the formation of volatile sulfur compounds. Those compounds likely derive from sulfur-containing amino acids. Riboflavin undergoes photo-activation when exposed to light at wavelengths of 370 nm and 440 nm, as detailed in AWRI Technical Note TN09.

Light-bodied white wines run the greatest risk from light exposure. They are often packaged in tinted wine bottles for protection. Wines packaged in clear, light green, and blue colored bottles are the most vulnerable. Dozon and Noble (1989) exposed still white wines in green glass to fluorescent lamps. A statistically significant lightstruck flavor appeared after 31.1 hours. The same wines in clear glass developed this flavor after only 3.3 hours, as cited by AWRI Technical Note TN09. Direct sunlight provides 4286 times the amount of UV-A radiation as fluorescent lamps, according to Gordon Watson (pers. comm., cited by AWRI Technical Note TN09). Rankine (1989) indicates that amber glass is most effective in excluding wavelengths below about 450 nm, as noted by AWRI Technical Note TN09. Light exposure can also exacerbate copper instability in susceptible white wines, leading to haze. The AWRI recommends protection from light if copper concentration exceeds approximately 0.5 mg/L. Visible signs of damage, such as label damage, can affect marketability. You can learn more about assessing bottle condition, including fill levels and condition.

Humidity Some degree of humidity is required to keep wines with cork enclosures from drying out. That holds even for bottles lying on their sides. Should the cork begin to dry out, it can allow oxygen to enter the bottle. The oxygen fills the ullage space and can make the wine spoil or oxidize. Conversely, excessive humidity can damage wine labels. That may hinder identification or hurt potential resale value.

Jancis Robinson notes that 75% humidity is the figure most often cited as ideal. There is very little significant research to definitively establish an optimal range. Tom Stevenson recommends that wine should not be kept in a refrigerator. The refrigeration process often includes dehumidifying, which can quickly dry out corks. Alexis Lichine recommends spreading half an inch of gravel on the floor of a wine cellar. Sprinkling it with some water from time to time maintains optimal humidity. A French study cited by Matt Kramer made a further claim. The relative humidity within a bottle is maintained at 100%, whatever the closure used or the orientation of the bottle. However, relative humidity above 50% is required for good elasticity of cork-based closures. A relative humidity above 80% has been found to increase the risk of mildew formation on the outer surface of cork (Lagorce-Tachon et al. 2016, Jackson and Lombard 1993, both cited by Chanut et al. 2023). For comprehensive advice on maintaining these conditions, consult the storage pillar.

Does bottle orientation matter for aging?

For most wines, horizontal storage is traditionally recommended to keep the cork moist. Sparkling wines often benefit from upright storage. Most wine racks are designed to allow a wine to be stored on its side. The thinking is that the cork stays moist and does not dry out in constant contact with the wine.

However, studies have shown varied results regarding the impact of orientation. Mas et al. (2002) investigated the impacts of different alignments on bottles sealed with six different closures for a white and red wine. As a general rule, wines stored upright had higher yellow/brown colour after 24 months than those stored horizontally. OD420nm absorbances measured that colour. The differences were not significant. The study showed that oxidation was higher for upright samples sealed with agglomerated cork stoppers. Elevated acetaldehyde levels appeared in white wine samples from the 3-month timepoint onwards, according to the AWRI. In another study, Skouroumounis et al. (2005) investigated the developmental characteristics of a wooded Chardonnay and Riesling wine, with samples stored under differing orientations. The testing covered yellow/brown colour (OD420nm), ascorbic acid, and sensory analysis. Bottle orientation, horizontal or upright, had little effect on the chemical composition and sensory properties of the two wines across a 60-month period, the AWRI reports.

Chanut et al. (2023) compared two storage positions. One was vertical, with the stopper in contact with the vapor phase. The other was horizontal, with the stopper in contact with the liquid phase. Position had no significant influence on the oxygen transfer, neither through the cork nor through the glass-cork interface. That held for microagglomerated corks in model wine over a 24-month aging period at 20°C.

For Champagne and other sparkling wines that they tend to age better if they are kept upright. This is because the internal pressure caused by the trapped carbonic gas provides enough humidity and protection from oxygen. The Comité Interprofessionnel du Vin de Champagne (CIVC) recommends storing Champagne on its side in a cool, dark, draft-free place. Three golden rules follow: constant, low ambient temperature (around 10°C/50°F), generous humidity, and no direct exposure to sunlight, noise, or excessive vibration, as stated by Comité Champagne. Regardless of orientation, proper storage is key to protecting your auction buying pillar decisions.

What about vibrations?

Anecdotal information suggests that vibration contributes to the accelerated aging of wine, with adverse effects. This remains a research area with relatively little data. A study by Chung et al. (2008) showed that vibrations of different frequencies had their own distinct effect on the chemistry of wine. The study concluded, "Vibration could be used to accelerate the ageing of wine, but in most cases, this may lead to negative effects on wine quality. Therefore, to store red wines with limited changes in physicochemical properties, vibrations should be minimized," according to Chung et al. (2008). Minimizing vibrations helps preserve the quality and potential appreciation of your fine wine investment.