What is the Goal of Wine Storage?

The goal of wine storage is to age premium wine or at a minimum preserve it. Preserving wine may seem simple because its an alcoholic beverage, but despite this, wine cannot be stored indefinitely. At the very least, someone who stores wine should know how long it can be stored.

The length of wine storage depends on the grape varieties used in the wine, where it was made, the maturity of the wine (how much time has passed since vintage date), whether or not it’s a premium wine (i.e. designed to age) and wine storage conditions. For a discussion on grape varieties and wine storage times see the following link:

The Best Types of Wine to Cellar

Ideal Wine Storage Conditions

• 55°F ambient temperature
• No more than 5 -10°F annual variation in temperature, 1 – 3°F daily variation in temperature
• 70% relative humidity
• Darkness
• No Vibrations

The Effects of Poor Temperature Control

So what’s so special about 55°F? Well technically wine can be stored safely between 40 and 65°F, as long as the temperature remains constant (you don’t want the temperature moving up and down in this range, it will ruin your wine). But the more you want from your wine, the closer to ideal wine storage conditions you want to be.

Rapid Aging: Heat increases the rate at which wine ages. Aging wine is a chemical process and like every chemical process, heat increases its reaction rate. For every 18°F increase in temperature, the aging rate of wine doubles. So, wine storage at room temperature (73°F) cuts its aging potential in half compared to 55°F.

Now this may not seem like a bad thing to some. After all, you can take that Cabernet Sauvignon that’s supposed to age for 10 years and cut its wine storage time in half at room temperature, right? Well, wine is a complex mix of amino acids, phenols, carbohydrates and other components that ordinarily are imperceptible to human senses. At about 70°F the reactions of these components accelerate to the point that they can be detected in the wine, causing off tastes and aromas.

Heat Damage: At temperatures above 80°F, wine is in danger of being cooked. How can you tell if a wine is cooked? It may smell of burnt sugar or stewed fruit instead of having vibrant fruit flavors and aromas. A slightly cooked wine may have dull aromas and flavors. High temperatures can also cause the wine bottle’s cork to protrude from the bottle neck, breaking the cork’s seal and exposing the wine to oxygen (the effects of oxidation are discussed below).

Slow Aging: At the other end of the spectrum, wines at temperatures below 50°F barely age at all. So, if you want to consume your age worthy wines within a reasonable time period, wine storage at these temperatures is not recommended.

Particles in the Wine: At low temperatures tartaric acid crystals may develop in the wine. They’re harmless, but unpleasant to see and taste.

Oxidation (Maderization): Oxidation is a natural part of the aging process. Wine reacts with the air in the unfilled part of the bottle (ullage), as well as with very small amounts of air that enter through the cork. As a result, wine that is introduced to excessive amounts of oxygen will age faster. That’s why an oxidized wine will taste like a dead wine or one that is past its peak.

How can you tell if a wine is oxidized? It will taste flat, the exposure to oxygen has taken out some of the volatile chemicals that are responsible for wine’s aroma. After repeated exposure, the color of the wine will begin to change. Red wines will take on a brick-red or even brown hue, whites will darken and take on a golden-brown or amber color.

What causes oxidation? Heat increases the rate at which wine is oxidized. On top of that, temperature spikes can break the seal of the cork exposing wine to air. But the most damaging way that wine is oxidized is through temperature fluctuations.

As a wine heats up it expands, putting pressure on the cork. As it cools down it contracts, creating a pressure differential which pulls air into the bottle. The more frequent the fluctuations, and the wider the temperature swings, the greater the exposure to air. In addition wine will begin to seep past the cork once the integrity of the seal is compromised, resulting in increased ullage (i.e. less wine and more air in the bottle).

White wines are more susceptible than red wines to heat and oxidation. That’s because red wines contain more tannins which act as antioxidants. With this in mind, you may want to store your white wines at a colder temperature, many experts suggest 45°F (once again you need to consider how this will affect aging time).

Note: Heat damaged wine should be consumed immediately, hopefully within 24hrs. It may still be palatable, but the longer you wait, the worse it gets. The wine cellar is not a hospital, wine faults get worse with age.

The Effects of Low Humidity

The discussion above clearly illustrates the importance of protecting the cork seal. Most people know that wine storage involves laying wine bottles on their side to keep the corks moist and elastic. But this only affects the cork inside the bottle.

To prevent the top of the cork from drying out, shrinking and cracking, the wine storage area needs at least 50% relative humidity (although it should be closer to 70%). Above 80%, mould is likely to form on the cork and label. This is primarily a cosmetic problem, but if you intend to sell your wine, have a large wine collection (since you need to be able to identify the bottle) or like to collect labels, keeping the label pristine is very important.

To protect your wine labels, you can wrap the wine bottles with saran (plastic) wrap.

The Effects of Ultra-Violet Light

Light-struck (or gouts de lumiere – French for tastes of light) is a term used to describe wines that have had excessive exposure to sunlight or fluorescent light (technically ultraviolet light in the wavelength of 325 to 450 nm). Delicate wines, like white and sparkling wines are the most likely to be affected, with the fault causing a wet-cardboard or wet-wool flavor and aroma (this phenomenon also affects beer, but causes a skunk smell). However, red wines rarely become light-struck because the polyphenols (tannins) present in the wine protect it.

The wine industry recognizes the need to protect wine from UV light, which is why they put wine in colored-glass bottles. However, the typical green-glass wine-bottle while offering some protection is not sufficient to block all the offending radiation (see study). That’s why it’s necessary to limit your wine’s exposure to sunlight and fluorescent light, or simply keep the wine storage area dark.

Minimizing Vibrations and Wine Storage

The jury is still out regarding the effects of vibration on wine. Vibrations may affect flavor and bouquet, but there have been no studies done that conclude that it’s detrimental to aging or preserving wines.

A study was conducted on the subject in 1962. It was done by Dr. Vernon L. Singleton Professor of Enology, Emeritus from the University of California at Davis and was titled Aging of Wines and Other Spirituous Products Accelerated by Physical Treatments. In that study, Dr. Singleton performed experiments to test the effects of vibration on wine maturation. The results are discussed in Matt Kramer’s book Making Sense of Wine (revised edition). Dr. Singleton is quoted as follows:

The only bad feature about vibration is possibly in dispersing sediments. You may, if you disperse them hard enough and often enough, find that it produces such fine particles that it fails to settle. So it may affect clarity, which in turn, can affect flavor. But barring that, I can say that vibration doesn’t make a difference. If you can look at a bottle of wine and it’s still clear, then it wasn’t vibrated enough to make a difference.

Therefore, following the traditional procedure of standing old red wine bottles up and letting the bitter sediment settle for a few days before serving should be sufficient to counteract this negative influence.

Typical Wine Storage Locations

Using Kitchens, Garages and Storage Sheds for Wine Storage

Without any kind of specialized equipment or modifications, the kitchen, garage and storage sheds are the worst places to keep your wine. The kitchen is one of the hottest places in the house, it also tends to be very well lit. It is subject to temperature fluctuations every time the stove or oven is being used and it contains lots of appliances that emit heat and vibrations.

Garages and storage sheds are rarely temperature controlled, so they tend to be very hot in summer, and very cold in winter. These places are generally not very clean, they may smell musty and have rodents that can chew wine packaging, corks and labels (not good if you want to sell your wine). They also tend to contain strong smelling substances like gasoline, solvents, paint and cleaning solutions whose odors can work their way into the wine through the cork.

Using The Basement for Wine Storage

Most people know that the basement is the ideal place to store your wine. It’s usually cool, dark and damp, but don’t take these conditions for granted. If your basement is not completely underground, store your wines against a sub-terrarium wall. Measure the temperature, humidity and temperature fluctuations so you know the conditions you’re dealing with (see below).

Make sure the basement is clean and free of strong-smelling odors. If the basement is particularly damp, don’t keep the wine stacked on the floor, especially if it’s in cardboard boxes. You should consider building or buying a wine rack system.

Wine racks can be bought prefabricated or as low-cost, do-it-yourself kits. Materials usually consist of stainless steel, wire grids or wood. Although stainless steel and wire grids are cheap, they are the least desirable because they tend to bend under the weight of the bottle, rust in humid conditions unless treated, and cause hot or cold spots through heat conduction.

Redwood is the best wine rack material because it’s naturally odor-free, doesn’t require staining or finishing (eliminating chemical off-gassing that might harm the wine), resists rot and mildew, and is strong relative to it’s weight so it doesn’t bend easily.

Softwoods such as Pine and Douglas fir are more prone to warping under moist conditions (unless sealed). But, they are good, low-cost options, mainly because they’re easier to work with and lighter to ship than hardwoods.

Using Closets and Other Indoor Spaces for Wine Storage

So, what do you do if you don’t have a basement? Look for closets, or other storage spaces in the interior of the house or apartment (i.e. away from exterior walls so they stay cool). Closets or storage spaces under stairs usually work well. If you can’t find an interior space, choose one against a shaded or northern wall.

Ultimately, you’re going to have to measure the conditions of the location you plan to use for wine storage. One of the most important tools you can own for this purpose is a thermometer / hygrometer which measures and records max / min temperatures and relative humidity. They’re not expensive, and they’re indispensable. If it comes down to a choice between a space with a higher but stable temperature, and one with cooler but fluctuating temperature, choose the one with the higher but stable temperature.

How do you protect and organize your wine in such small confines? Modular plastic containers work well. Storvino makes wine storage containers of recycled polyethylene. They’re cheap, light, expandable, don’t warp and don’t require carpentry skills.

Another useful tool is the polystyrene (Styrofoam) wine box. If you order wine online or if wine has ever been shipped to you, you probably know what it is and may even have a few stashed away somewhere. They’re great for minimizing the effects of temperature fluctuations. If you don’t have any lying around, you can order them from shipping companies like U-Line.

Big wine bottles like Magnums and Jeroboams are less susceptible to temperature fluctuations. The larger volume of liquid in a big wine bottle takes longer to warm up or cool down, making the temperature fluctuations smaller and less frequent. So, if you can afford to buy large-format wine bottles, they hold up better than standard bottles in less-than-ideal conditions.

Wine storage under these conditions is a short-term solution. You should not store wine longer than 6 months at room temperature.

Using The Refrigerator for Wine Storage

Refrigerators are great at preserving perishables for short periods of time. They are not meant for long-term wine storage. Don’t confuse preservation of an unfinished bottle of wine (for a few days or a week) with aging wine. Refrigerators are simply too cold, they maintain temperatures of 40°F or less, and as mentioned above, very little if any aging occurs at these temperatures.

Refrigerators do not maintain a constant temperature. The heart of the refrigerator’s cooling system is the compressor. The compressor cycles on and off based on the temperature setting of the thermostat in the refrigerator. The thermostat only establishes the set point, but the actual temperature can vary by several degrees above or below the set point.

Temperature varies because once the set point temperature is achieved, the compressor switches off, and depending on the system will come back on after the temperature has warmed 3 to 5°F. This doesn’t occur daily, this temperature fluctuation occurs every cycle (every half hour?). This is done to preserve energy and to prevent the compressor from burning out by constantly turning on and off. Temperature fluctuations can also be caused by automatic defrosting cycles in frost-free refrigerators and constantly opening the refrigerator door.

Refrigerators are also very low in humidity. Depending on the system, relative humidity can vary between 17 and 40%. At the low end are refrigerators that share air with a freezer, which strips humidity from the air. At the high end are systems where the refrigerator and freezer are isolated from each other, or refrigerators with no freezer.

You also don’t want to store your wine with food, especially food with strong odors (i.e. onions, garlic). You can bet that in the small confines of a refrigerator, these odors will work their way into the wine through the cork (making your wine taste like the strong smelling offender). You should also keep wine away from fermented foods or foods likely to ferment (i.e. cheese, fruit, vegetables), anything with its own yeasts can wreak havoc with a wine’s development.

Alternatives When Using a Refrigerator for Wine Storage

A spare refrigerator makes a better wine storage location than the refrigerator you use everyday to store food. If you use it exclusively for storing wine you can reduce the temperature fluctuations by filling the refrigerator completely with wine or, filling empty space with bottles of water. This is a cooling block and will retain temperature much better than the surrounding air. Using a spare refrigerator also means you are less likely to cause temperature fluctuations by constantly opening the door.

There is a piece of equipment used by homemade-beer brewers that has been adopted by wine enthusiasts to control temperature in a refrigerator or freezer. This temperature controller (both digital and analog controllers available) can be used to maintain the refrigerator or freezer’s temperature at optimum for wine storage (55°F). The analog controller made by Johnson Controls can maintain temperature + / – 3.5°F, the digital made by Ranco can maintain temperature + / – 1.5°F (with the digital you can specify temperature range). The equipment is easy to use if you buy it pre-wired, you simply plug the controller into an outlet, and plug the refrigerator into the controller.

Using this equipment on a spare refrigerator and packing it tightly with wine or water bottles, should control temperature satisfactorily for wine storage. However, using a temperature controller on your refrigerator can possibly shorten the life of your compressor. In addition, you have to increase the relative humidity inside the refrigerator if you want to store wine for more than a year. Putting a bowl of water inside may help, but the results will probably be erratic (this should be monitored with a thermometer / hygrometer, see above).

If you don’t have a spare refrigerator, a wine refrigerator or cooler is an acceptable short-term solution (less than a year). The problems of a wine refrigerator are essentially the same as a regular refrigerator except it operates at warmer temperatures. Its primary purpose is to keep wine at proper serving temperatures, not age wine for ten years.

For long-term storage (or aging wine) you should consider buying a wine storage cabinet. They’re designed to maintain ideal wine storage conditions, but are considerably more expensive than a wine refrigerator.