Aging wine in oak tends to improve the flavor.

Grapes are crushed for their juice. Wine yeast is added to the juice, which ferments and becomes wine. The wine is bottled and stored for aging.

In the production of wine, after fermentation, some wines are ready to go into a bottle and then to be consumed. Some wines mellow/develop/improve from barrel aging before bottling and some will benefit from both barrel aging as well as aging in the bottle.

Knowing the type of wine you have, you can determine 'when' the wine has matured and is ready to drink. That would be the 'time' to drink it. So the phrase is encouraging wine lovers to let the wine mature before you open it.

Angel's Share

Some studies had found anti aging benefits of Resveratrol, a substance found in grapes and wine. However, there is no conclusive evidence as such and there is still debate in the scientific community.