[snip] In the Celtic legend of Bran the Blessed, the cauldron appears as a vessel of wisdom and rebirth. Bran, mighty warrior-god, obtains a magical cauldron from Cerridwen (in disguise as a giantess) who had been expelled from a lake in Ireland, which represents the Otherworld of Celtic lore. The cauldron can resurrect the corpse of dead warriors placed inside it (this scene is believed to be depicted on the Gundestrup Cauldron). Bran gives his sister Branwen and her new husband Math — the King of Ireland — the cauldron as a wedding gift, but when war breaks out Bran sets out to take the valuable gift back. He is accompanied by a band of a loyal knights with him, but only seven return home. [/snip]
https://www.learnreligions.com/cerridwen-keeper-of-the-cauldron-2561960
Ah, a magic cauldron! That explains its superior properties of preservation. :)
However, I don’t think giantesses expelled from boggy ponds in Ireland is any way to serve drinks.
Not that I’d want a drink from a jug that had a fetid warrior corpse stored in it. Probably smell too much like elderberries.