The Brine Cellars is a real delve. Its monsters have more health and hit harder than out in the world, the smuggler is dangerous, and Old Barrelback is a proper fight. It's made for two or three players with food. A lone player with food can still win.
Corin Vale's "Down the Cellar Steps" opens after Catch of the Day and Tools of the Trade. He tells you plainly to bring food and a friend.
Every clear pays a reward. Each player who fought Old Barrelback gets a Barrelback Buckler or a Cellar Lamp Wand, every time.
The Brine Cellars no longer promises an end chest. The party card shows what a clear actually pays.