There are some small tricks which makes it possible to understand how the refinement in bottle of “big” red wines works.
One among all is, surely that to observe the level of the wine on the neck of the bottle: if the neck of the bottle is nearly empty and wine is withdrawn below, in the lower part of the shoulder where the neck widens it will mean that the cork has given its results. Too much air could have arrived and the wine, almost always, has been lost.
To have an optimal conservation the amount of air that filters in the space glass / cork must be almost invalid. To verify this it should be observed the space among the cork and the wine