A mug of mead

 is a consumable product, able to restore a relatively small amount of health and a moderate amount of energy. It can be brewed at varying quality levels using a brewing stand. The quality of the crafts depend on the quality of the hops used.

Quest
The crafting recipe can be obtained from Horadric after opening the buffet on Witch Hill. Rumors of the high quality beer served at witch burnings make Horadric curious, asking the player for. After bringing him the beer Horadric will reward the player with the recipe for a mug of mead.

Trading
With the DLC Stranger Sins, mugs of mead - as with most beverages - may be sold regularly, either passively by being stored in the Talking Skulls cellar, or actively by being stored in the Barmans inventory and triggering an event.