Ale is a beverage/potion made at a Keg with 1 Mug. Inflicts Tipsy, increasing melee abilities, lowering defense by 2% and lasting for 2 minutes. After drinking the ale, the mug used to craft it is not given back.
Once a mug has been crafted into Ale, it cannot be used as a decoration.
Ale is best used against monsters with high health, but low attack.
Due to the defense loss suffered on consumption, Ale is not good to drink while battling a boss. Although, using an Ironskin Potion can be a good way to counter the defense decrease.
Despite the fact that it's considered a "buff" potion, once drunk the icon cannot be removed by right-clicking. Considering that, it may be classified as a "debuff."
Getting healed by the Nurse will remove the effects, further indicating debuff nature.