Guinness is a stout, a dark, rich brewed beverage with roasted barley. Actually, I can't be sure exactly how old the bottle I had was. It was supposedly among the cases that were just manufactured, and ready for distribution.

A lot of the finer wines and liquors supposedly mature with age, giving the product fullness, but I haven't been able to appreciate the distinction fully.

Beer, Lager, etc. are brewed and actually can become stale over time.