Idea:
The barrel label with the contents isn't always visible, but the barrel lid is. Half of the barrels have a textured surface on the top, allowing you to determine, at least roughly, what's inside.
Suggestion:
It would be nice if all barrels had this.
Options:
- a small, shiny water stain on the lid of a barrel containing water
- a handprint in the color of the dye on barrels containing dye
- a handful of berries on a barrel containing juice
- perhaps drinking vessels depending on the barrel's contents: a beer mug, a birch mug, a wine glass, a clay teapot