In a cellar, it is usually necessary to maintain a relative humidity level of between 55% and 75%. When ambient humidity falls below 40%, the cap may dry and the breathing between the outside and the inside of the bottle will no longer be adequate. The wine can therefore flow and oxidize more. Beyond 80%, molds can affect labels and produce bad odors. It is therefore important to have adequate ventilation. And then, a little cleaning once or twice a year does not do any harm at all, just be delicate.