Question about aged wine?

The tannins don't align to the magnetic pole, they polymerize. This means smaller chains of molecules bond together to make longer chains of molecules thus softening the tannins and producing more complex flavors. These are also technically oxidation reactions, though high amounts of oxygen will ruin a wine, a small amount is needed so the wine doesn't go through reduction, hence why a natural cork is still required for all wines meant to be aged.