A lot happens to a bottle of wine as it ages. The color deepens, the taste mellows, and the bouquet expands, and while most of this change is driven by the wine’s internal chemistry, it all depends on one major external factor: temperature, which is why finding the right red wine storage temperature is so important. Storing red wine at the wrong temperature can ruin it in a few hours. Storing it at the right temperature can preserve it for years.Red wine is a complex and evolving solution of chemicals and organic compounds: water, ethanol, glycerol, tannins, phenolics, organic acids, anthocyanins, and flavanols. Even in a store-bought bottle, so many interactions are occurring that even experts still don’t fully understand their effects. What they do know is that that because it lacks sufficient alcohol to preserve it, it will eventually go bad. Its low alcohol content is primary reason why, even though wine making has been going on for centuries, the science of wine storage is still in its relative infancy. It wasn’t until the 16th century that wine makers discovered the effects of acidity and oxygen on wine preservation, and it wasn’t until the 17th century that they began storing it in corked bottles.
Effects of Aging on Red Wine
There are three things that affect red wine during the aging process: light, humidity, and temperature. Light, especially ultraviolet light, breaks down the complex flavor molecules in red wine. Humidity affects the cork. Too little and the cork dries out, shrinks, or cracks, which lets oxygen into the bottle. Too much, and mold spores can form, rot the cork, and ruin the wine. Temperature alters the wine’s delicate chemistry, either transforming it into a delicate blend of flavors or a dreary mishmash. There are at least three ways heat impacts the development of red wine, each of which is important to your final enjoyment.
Effect on Taste
The first and most noticeable effect of age is on the wine’s taste. Fresh red wine is high in tannins, organic molecules found in grape skins, grape seeds, and oak barrels. They’re noticeable for their bitter, astringent taste and the distinctive dryness they leave behind after you drink them. It happens because tannins bind to the proteins that lubricate our saliva, which is why red wine is paired with red meat. It minimizes this effect.
As wine ages, tannins bind together and form long molecules chains in a process known as polymerization. Once these chains get long enough, they drop out of the chemical solution at settle at the bottom of the bottle. If you’ve ever noticed a layer of sediment in your wine, it’s the result of polymerization. Over time, it removes the wine’s bitter taste, making it smoother, lusher, and more rounded. Most of the tannins in wine come from grapes and grapes seeds. A few come from the oak barrels they’re aged in, which is why aged wine tends to have an oaky taste. As grape tannins drop out, the oaky ones become more noticeable.
Effect on Color
One of the other molecules tannins bind to are anthocyanins, water-soluble pigments that give wine its color. Fresh red wine is bright red with a purplish tint, but as it ages, and the wine’s monomeric anthocyanins polymerize and the color changes to brick red and then eventually to brown, which is a sign it’s gone bad.
Effect on Aroma
Humans are only capable of detecting five basic flavors: sweet, sour, salty, bitter, and unami (meaty or savory). These five flavors aren’t capable of creating the full range of complex tastes you enjoy in a bottle of red wine. Those come from the wine’s aroma, which is actually a combination of three different aromas produced during different parts of the wine making process. The first is the varietal aromas, which come from the grapes. The second is the vinous aromas, produced during fermentation. and the last are the tertiary aromas, which come from a series of organic compounds called esters that are created when the acids in the wine interact with the alcohol. These interactions continue throughout the aging process, even as the varietal and vinous aromas grow weaker. A properly aged bottle of red wines might contain over 200 esters and they’re what give wine its delicious bouquet. Esters are used to create an extremely wide range of aromas. Common ones include plum, mint, tobacco, vanilla, pine, pepper, almond, truffle, chocolate, coffee, caramel, cinnamon, or smoke.
Impact of Temperature on Red Wine
All of these chemical reactions speed up as the temperature increases. Reactions that might have taken several years at low temperatures might take place in several months or several hours at high temperatures. So how come people are so afraid of storing red wine at high temperatures? Because not every chemical reaction reacts to heat the same way. They all have different heat thresholds. Some require small amounts of heat and some require more. Tannins, for example, polymerize at lower temperatures while sugars react at higher temperatures. Exposing the wine to excess heat ruins the internal chemistry that gives it its flavor. At 55°F, all of these reactions proceed at roughly the same rate, which is why its considered the optimal red wine storage temperature.
High temperatures also encourages the formation of acetic acid, which is formed when bacteria (Acetobacter aceti) in the air come into contact with alcohol. Acetic acid is one of the main components in vinegar and the bacteria that produce it thrive at high temperatures, which is another reason why experts recommend storing all your wine at 55°F.
Storing red wine at sub-optimal temperatures is also harmful, though not nearly to the same degree. Some reactions will still proceed quicker than others, but the rate of reaction is usually slow enough that it won’t seriously damage your wine if you’re only storing it at those temperatures for a short period of time. It will be a major problem if you’re storing premium wines, which are meant to be aged for several years before drinking. Storage temperatures below 55°F will prevent them from developing their full richness and flavor.
Importance of Temperature Stability
Storing red wine at a stable temperature is even more important than storing it at the right temperature. Temperature fluctuations increase the rate of oxidation. All wine bottles are sealed with small amounts of air inside and if they’re sealed with a cork, they’ll absorb more over time. Small amounts of oxygen are vital to the aging process. In small doses, it helps reduce astringency and promotes the growth of aldehyde, an organic compound derived from alcohol. In small amounts, aldehyde stabilizes the wine’s color, taste, and texture, and improves it’s bouquet. It’s responsible for the apple, sherry, and nut flavors in red wine, but in large amounts, aldehyde gives wine a stale, acridic flavor, and is one of the major contributors to its decline. Oxygen also encourages bacterial growth and negatively affect phenolic compounds, such as tannins, and unbalance the wine’s flavor.
In an unstable environment, the wine in the bottle is constantly expanding and contracting with the ambient temperature. As it expands, it loosens the cork, allowing small amounts of small amounts of wine to seep out and a small amount of air to seep in. When temperatures fall, the wine contracts, which pulls in more air. The longer this process continues, the more air leaks into the bottle and the more oxygenated the wine becomes. Any fluctuation more than 5°F above or below optimal storage temperature is harmful, even if it occurs over the space of several months, which is why a proper cellar or wine cooler is essential if you’re going to be storing wine for a long period of time. They’re the only way to minimize these sorts of temperature fluctuations.
Storing Red Wine for Short Periods
The one exception to the red wine temperature rule of 55°F is if you’re storing wine you intend to drink the same day. Then it’s generally a good idea to store red wine at its serving temperature instead of its storage temperature. Light, fruity reds should be served slightly chilled, while full bodied reds should be served a little under room temperature.
|Red Wine Serving Temperatures|
|Dolcetto, Cotes du Rhone||55°F|
|Chinon, Port, Maderia||57°F|
|Rioja, Pino Noir, CDP||61°F|
|Bordeaux, Cabernet Sauvignon, Shiraz||65°F|
The reason for this exception is because the temperature of your wine affects your enjoyment of it. When you chill red wine, the tannins become more perceptible and the wine tastes tart, bitter, and acidic. Chilling red wine also reduces its aroma, which dampens its flavor. If you don’t have a dual zone wine cooler capable of warming wine bottles separately, take your wine out of the cooler fifteen to thirty minutes before serving so they can warm up to the appropriate temperature.
The majority of the wine sold today is sold ready-to-drink. It’s already been aged by the winery, so it won’t improve much with time, at least in most cases. Finding the ideal red wine storage temperature isn’t about improving flavor as it is about preserving wine and preventing spoilage. If you’re interested in aging a bottle to see what sort of flavors it produces, choose a wine with lots of tannins and a high alcohol content, as those wines will age best. If you’re saving some red wine for a special occasion or stocking up on your favorite label, storing it at the right temperature is the only way to ensure it’s still ready to drink when you open it.