When you drink beer, there is a chance that you will gain a beer tasting point, based on what you've drunk before and your own personal characteristics. The higher your skill, the harder it is to gain points.
When you have 7 beer tasting points, you gain one additional permanent perception point. You gain a second permanent point at 49 beer tasting.
See also: Beer, Gastronomy, Oenology and Fumeology