To find the mission "A Venerable Vintage," head directly west from the Imperial City
across the bridge leading into Weye and the Wawnet Inn. Head inside the Wawnet Inn and
find a woman named Nerussa, talk to her and accept her quest to find 6 bottles of
Shadowbanish Wine. Here are the locations where you can find Shadowbanish Wine:

    *  Fort Aurus (located along Niben Bay, north of Fort Grief.) – There is a chest
containing two bottles at the northeast side in the very back room of the dungeon.
    * Fort Carmala (directly south of the Chorrol stables.) – There is a chest containing
two bottles deep into the dungeons.
    * Fort Dirich (located northwest of Skingrad.) – Deep down in the dungeon guarded by a
ghost (at level 5) in a crate between the wall and the raised coffin in the middle of the
hall. (2 bottles)
    * Fort Grief (located on an island in the middle of Niben Bay in southern Cyrodiil.) –
There is a chest containing two bottles in the outside top level of this fort.
    * Fort Irony (located south of the Niben Bay, on the left side of where it heads into
the Lower Niben, across from the entry of the Panther River.) – In a chest in a room where
the entrance to cave section. (2 bottles)
    * Fort Magia (located east of the Imperial City, it's located on the road around the
Imperial City south of the road heading towards Cheydinhal.) – Towards the end of the
dungeon trawl in a passageway of the Garrison Blocks. (2 Bottles)
    * Fort Scinia (located southeast of the Cheydinhal, deep within the Valus Mountains.)
– In the Hall of Legends area of the dungeon. (2 bottles)
    * Fort Vlastarus (located east of Skingrad, south of the Gold Road. It is northeast of
Gro-Bak Camp.) – There is a chest containing two bottles behind a pillar in one of the
rooms.
    * Frostcrag Spire (Located high in the Jerall Mountains of Cyrodiil away from prying
eyes, this is an add on so you may not have it.) – On the wine rack in the storage area.
(1 bottle)
    * Battlehorn Castle (located west of Chorrol near the end of the Black Road as it
heads towards Hammerfell.) – On the wine rack in the castle wine cellar. (1 bottle) 

Once you find the 6 bottles, return to her and she will give you 1000 gold, and 100 gold
for each additional bottle.

Enjoy!