A wine cellar can be as small as a kitchen cabinet or as big as the maze of secret passages underground a castle.
It does not matter as long as conditions are right for storage and maturation of wine.
Your perfect wine cellar should...
- be cool, with a temperature between 50º and 60º F (10º and 15º C)
- the temperature should keep pretty constant
- the area should be on the damp side, a humidity of 75% is ideal
- humidity should not be higher than 95%
- be free of vibrations that can travel through wine
- be dark, no direct sunlight
- free from chemical odors
- have shelves that allow bottles to lay on their sides.
If you have a room like this, dark, cool and damp all year round, you have what is called a passive wine cellar. A passive wine cellar like this is the ideal place to store wine, unhappily this sort of conditions only happen in deep underground cellars with thick stone walls. Unhappily, only old mansions built in stone would have this sort of cellar.
Three inch thick polyurethane has been recommended as a good choice.
Some basement rooms have the potential to become wine cellars with the right insulation. Look for some insulating material which is odorless, does not absorb moisture and makes a perfect seal. If the room is well insulated, the change in temperature will be very slow even without a cooling unit.
Possible problems with your wine cellar
Slightly higher temperatures than the optimal 50 to 60º F (10 to 15º C) are not a major concern; the wine will mature more quickly though it would be slightly less satisfactory.
Changes in temperature are not good for the wine; temperature variation causes much more most harm than having a temperature slightly higher than the desired level.
Dry cellars can cause corks to dry out, contract and let air into the bottle, the air will oxidize the wine, turning it into vinegar in the long run.
Mold grows when the humidity level is higher than 95%, and mold is no good for the wine.
Too much movement or shaking can spoil wine. Avoid storage next to machines with a motor engine, such as refrigerators and washing machines, and avoid unnecessary handling or transportation.
Do not keep good wine in the refrigerator for longer than necessary. Too much cold will numb the flavor and the fridge engine is harmful the wine.
Avoid direct sunlight as the UV rays are especially dangerous to wine.
Don't keep your wine next to rests of paint, varnish or paint removers, their fumes can diffuse through the porous cork and spoil the flavor.
Constant contact between cork and liquid prevents the cork from drying out. Sparkling wines and wines with a screw cap can be stored upright.
The kind of insulation that absorbs moisture from your cooling unit.