Temperature Swings in Wine Storage: What You Need to Know

Minimising temperature swings in wine storage is critical for preserving your fine wine. Fluctuations can lead to physical damage and accelerate undesirable chemical reactions. The Australian Wine Research Institute (AWRI) advises avoiding thermal cycling, where temperature varies significantly. Wine's thermal expansion can cause cork stoppers to move or wine to leak when exposed to temperatures "significantly greater than ambient temperature." Such physical damage does not necessarily imply compromised quality. Even so, the AWRI notes it "will obviously affect the appearance, and therefore the marketability, of the wine." Research by Chanut et al. (2023) on microagglomerated cork wafers in model wine demonstrated a clear effect. High storage temperatures, such as 35°C or 50°C, strongly increase oxygen transfer at the glass-cork interface, potentially leading to leakage. Wine is "very susceptible to changes in temperature," and prolonged exposure to temperatures exceeding 77°F (25°C) can spoil wine or cause "off-flavors that taste raisiny or stewed."

How do temperature swings affect your wine?

Temperature swings can significantly impact your wine by causing both physical damage and accelerating chemical changes. The AWRI recommends avoiding thermal cycling, where temperature varies significantly between day and night. Leakage of wine or movement of cork stoppers can result from the thermal expansion of wine. That happens at temperatures "significantly greater than ambient temperature," as noted by the AWRI. Such physical damage "does not necessarily imply that the quality of the wine has also been affected," but it "will obviously affect the appearance, and therefore the marketability, of the wine," according to the AWRI.

Chanut et al. (2023) studied microagglomerated cork wafers in a miniaturized bottle system with model wine. They found the oxygen diffusion coefficient of the cork stopper alone remained unchanged, regardless of storage conditions over 24 months. Temperature significantly impacted the total oxygen transfer at the glass-cork interface. At 20°C, the presence of model wine favored oxygen transfer at this interface. It accounted for nearly 75% of the total oxygen transfer. The comparison was cork studied without model wine, as per Chanut et al. (2023).

At higher storage temperatures, the barrier properties of the bottleneck-cork system were notably altered. Chanut et al. (2023) observed the effect at 35°C, a temperature "easily reached during bottle shipping," as they put it. A significant transfer at the glass-cork interface began to occur after nine months of storage. At 50°C, this shift was evident within the first three months of storage. It led to a "tremendous oxygen transfer" at the glass-cork interface. That approached the diffusion coefficient of oxygen in the air and indicated leakage, according to Chanut et al. (2023). This increased transfer and leakage could be attributed to a partial melting of the paraffin and silicone surface treatment on the cork stopper. A modification of its mechanical properties is the other candidate, as Chanut et al. (2023) suggest.

Beyond physical damage, wine is "very susceptible to changes in temperature." Temperature control is a critical consideration in storage. If wine is exposed to temperatures exceeding 77°F (25°C) for long periods, it "may be spoiled or become "corked" and develop off-flavors that taste raisiny or stewed,". The AWRI, citing Ough (1986), goes further on heat. Temperatures in excess of 40°C can induce visual and sensory changes in a wine in "only a matter of days," it notes. Marais (1986) observed the development of faulty flavors and decreasing overall quality after 12 months' storage of wine at 30°C. Conversely, if wine is exposed to temperatures that are too cold, it can freeze and expand. That can push the cork out or crack the bottle. More oxygen then reaches the wine. Temperature swings can also cause adverse chemical reactions in the wine. Repeatedly moving wine from a warm room to a cool refrigerator is one example. Those reactions may lead to various wine faults. Our guide to wine ullage levels explained covers how these changes affect fill levels.

What are the ideal temperature and humidity for wine storage?

The ideal conditions for wine storage involve consistent, cool temperatures and controlled humidity. Those ensure slow, graceful aging. Most experts recommend keeping wine at constant temperatures between 50 and 59°F (10 and 15°C). Jancis Robinson is among them. 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, takes a different view. He believes that wine can be exposed to temperatures as high as 120°F (49°C) for a few hours and not be damaged. Amon and Simpson (1986), cited by the AWRI Technical Note TN09, recommend storing bottled wine with the cork in contact with the wine. The location should be cool (15-20°C) and dry.

For humidity that 75% humidity is often cited as ideal. However, "there is very little significant research to definitively establish an optimal range." Low humidity can cause corks to dry out, allowing oxygen to enter the bottle. Excessive humidity can damage wine labels. Climate Controlled Wine Storage maintains moderate humidity levels of 55%-75% to avoid these issues. 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 suggests spreading half an inch of gravel on a cellar floor. Periodically sprinkling it with water maintains optimal humidity.

For Champagne, the Comité Champagne states that bottles can be stored upright or on their sides. They belong in a cool place, at a constant temperature of between 10 and 15°C. Humidity must be high and constant, between 60% and 80%, for Champagne, according to the Comité Champagne.

Here is a summary of recommended storage conditions:

Recommended Temperature	Recommended Humidity	Notes
50-59°F (10-15°C) constant	75% (cited as ideal, but little research)	Most experts recommend this range.
52°F (11°C)	Avoid refrigeration (dehumidifying)	Speculates this as most ideal.
~55°F (13°C) constant	Not specified	For wine intended for aging.
15-20°C (cool)	Dry	Cork in contact with wine.
10-15°C constant	60-80% high and constant	For Champagne.
Stable temperature	55-75% moderate	To avoid cork shrinkage/leakage or mold.

Does bottle orientation matter for temperature swing impact?

Traditional advice suggests horizontal storage for corks. Research indicates that for oxygen transfer it may not be critical, and Champagne benefits from upright storage. Most wine racks are designed to allow wine to be stored on its side. The idea is that the cork is more likely to stay moist in constant contact with the wine. However, research in the late 1990s suggested that storing bottles at a slight angle is ideal. This allows the cork to maintain partial contact with the wine and stay damp. It also keeps the air bubble formed by a wine's ullage at the top. On a bottle lying flat, that bubble sits in the middle instead. Keeping the ullage near the top, it has been argued, allows for a slower and more gradual oxidation and maturation process. If the wine is completely on its side, temperature variations can eject wine through the cork. That repeatedly introduces oxygen into the bottle.

A study by Chanut et al. (2023) looked at microagglomerated cork wafers in model wine at 20°C. It 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 through the cork or at the glass-cork interface over a 24-month period. This finding aligns with results from Lopes et al. (2006) and Hirlam et al. (2019), as cited by Chanut et al. (2023). Those studies reported similar oxygen transmission rates for bottles with microagglomerated stoppers stored vertically or horizontally. The AWRI also cites studies by Mas et al. (2002) and Skouroumounis et al. (2005). Those found that bottle orientation had little significant effect on color, or on chemical and sensory properties, for certain wines over extended periods.

For Champagne, the Comité Champagne states that bottles "can be stored upright or on their sides." Champagne and other sparkling wines tend to age better if they are kept upright. The internal pressure from the trapped carbonic gas provides enough humidity and protection from oxygen.

How can you protect your wine from temperature swings?

Protecting your wine from temperature swings requires implementing insulated and temperature-controlled storage solutions. The AWRI Technical Note TN09 recommends storing wine under "insulated and/or temperature- controlled storage conditions, which minimise fluctuations in both temperature and humidity." This technical note also suggests using miniature temperature logging devices. They monitor temperature fluctuations during storage and transport.

Wine will develop prematurely if stored in an environment with large and frequent temperature variations. Temperature control systems are crucial to keep the wine cellar temperature stable. That prevents corks from expanding and contracting, which can lead to oxidation of the wine. Climate Controlled Wine Storage maintains stable temperatures and moderate humidity levels (55%-75%). That prevents cork shrinkage and leakage, or mold and contamination, and assists optimal wine development.

Beyond temperature control, other measures can help. We suggest storing wines in corrugated boxes or wooden crates. That protects them from direct light. Light-bodied white wines are most susceptible to light exposure. They often come in tinted bottles for protection. Wines in clear, light green, and blue bottles are more vulnerable. They may require additional precautions.

Proper storage is a cornerstone of fine wine investment. It safeguards both the wine's quality and its market value. When you buy wine at auction, understanding its provenance and storage history is vital. Consider reviewing our comprehensive guide on how to store wine for further details. Optimal storage and transport carry costs of their own. Our landed cost calculator can provide valuable insights.

Market dynamics and condition influence your collection's value. Track its performance with our live Fine Wine Market Index.