The Ideal Temperature and Humidity Levels in Wine Cellars

Cellar temperatures should be between 55 to 57 degrees Fahrenheit and humidity should range between 60 to 70 percent.

Colder temperatures will throw the wine into a dormant state and would end up tasting flat instead of being fruity and sparkling. The aging process involves several chemical reactions in the wine that are vital for the development of the wine’s natural aroma and flavor. These essential chemical reactions occur in a naturally orchestrated manner over an ideal period of time. Very low temperatures will slow down these occurrences to a point where they bear little contribution to the aging of the wine. Simply put, lower temperatures would make the maturation period take longer than it normally takes. Wine cellar refrigeration systems maintain the ideal cellar temperature of about 55 degrees Fahrenheit that allows wine to mature within the normal life cycles of most humans.

With higher temperatures, you risk cooking the wine and aging it prematurely. Higher storage temperatures speed up the chemical reactions that normally occur in wine. Unfortunately, even the undesirable ones are accelerated as well. Wine naturally contains organic compounds that create off tastes and nasty odors. Extended exposure to higher temperatures, even in short periods, accelerate these reactions that make the wine end up with an uncharacteristic brown color and syrup-like taste. Needless to say, wine cellar refrigeration systems prevent these factors from happening. Wine refrigeration units also prevent frequent temperature fluctuations. These relatively fast changes in temperature throw the naturally coordinated chemical reactions in wine out of sync.

Lower humidity levels can make the corks excessively dry. This increases the rate of airflow in the corks which might result in oxidation. Oxidation breaks down vital organic compounds (phenols) that are responsible for creating the exact aroma, color and taste expected for that specific wine. Aside from phenols, the ethanol present in wine can likewise oxidize into other compounds that may cause some flavor taints. Additionally, excessively dry corks also let the wine to evaporate at a considerably faster rate.

Higher humidity levels, might allow mold to grow on your corks and labels, and eventually, on your wine racks as well. The same ideal climate conditions found in wine cellars are also the perfect conditions where molds can grow. Although corks usually keep the mold from touching your wine but the exposed part of the cork will. Aside from the wine itself, labels and corks largely determine the value of wine and molds would simply ruin them. Wine cooling units prevent excessive humidity by turning humid air into liquid, which is collected outside the wine cellar.

The Wine Cellar

Even though the most important element of custom wine cellars is the wine cooling unit, you must build the wine cellar properly too for it to be effective. The following are a few key notes to consider.

R-value is the rate at which an insulator lessens the flow of heat through walls. Exterior walls and ceilings must at least have R19 insulation while interior walls require R11 insulation. Rigid foam and fiberglass are the most efficient insulators because they characteristically higher R-values.

Walls and ceilings must be installed with a vapor barrier using a 6 mil plastic sheeting, preferably on the warm side of the wall. The most commonly used method is to wrap all interior walls, leaving the plastic loose in the stud cavity so the insulation can be placed in between studs. Use moisture resistant materials such as green boards for wall finishing.

Wine cellar doors must at the least be weather stripped and insulated. A threshold system should be present. Use insulated glass units (IGU) for windows and glass doors.

Lights emit excess heat so use them minimally. Extended exposure to light also results in the breaking down of otherwise stable organic compounds naturally found in wine.

Split Cooling versus Self Contained Cooling

Wine cellar cooling units consist of primarily two individual parts. The condenser unit provides refrigerant liquid to the evaporator unit via a compressor. The condenser unit cools vapors that are then compressed and funneled through heat exchange coils, where the refrigerant is condensed into liquid form. The evaporator unit, which is normally located within the wine cellar room, cools the humid air that it comes into contact with by turning it into liquid.

There are basically 2 basic types of wine cellar cooling units: split cooling systems and self contained systems. Split Systems have the two main components mounted separate from each other. With split systems, the condenser unit is usually situated externally for easier access to vapor gasses, which it compresses into refrigerants. The evaporator unit is installed inside the wine room where refrigerant liquid is supplied through pipelines. Self-Contained Systems have the two components contained in a single housing unit. They’re usually mounted through the wine cellar wall with an adjoining room as exhaust area.

Split systems, meanwhile, comes in handy when dealing with site difficulties. You could simply install the two components in their proper locations and then use pipes in connecting them with each other. On the other hand this wine refrigeration unit is considerably more expensive than self contained ones. An HVAC (Heating, Ventilating and Air Conditioning) professional is required to install it. Ideally, the two components must at least be50 linear feet from each other, which means that the condenser probably would have to be situated outside the house. This means extra costs for the condenser housing, pipelines and power source.

Self contained systems, meanwhile, are more affordable and simple to install. But it produces a great deal of noise during normal operations and usually necessitates a suitably sized adjacent area for an exhaust room. This adjacent room, by the way, have to be climate controlled too making this system inappropriate for exterior walls. This problem can be solved by using the ducted self-contained system but this would mean additional installation and operations costs.

Recent technological innovations brought about a third type: the Ducted Self-Contained System. As the name implies, it’s basically a self-contained type but now, air ducts are used to ventilate the air. This third type has proven to be the most complete type since it provides many convenient options.

Coastal Custom Wine Cellars installs wine cellar cooling systems using popular brands of cooling units. Additionally, view this youtube video for a visual look into their wine cellar design process.