In cellars, with lower temperatures wine contracts an we can observe every years some lost. This lost is about absorption or evaporation (the famous "part des anges"). 

We need to check every barrels and the tooling is a process which consist to stabilize every barrels full in adding regularly wine (or armagnac) of same quality. The goal is to avoid oxydation ! 

With our 900 oak barrels, tooling is taking some times !