Just have a couple of ideas for improved barrels:
Stacking barrels standing for better, more consistent long term storage. you wouldn't be able to open a barrel that's not on top.
Stand for stacking barrels laying down. To create that classic vine cellar look. barrels laying down can't be opened.
The ability to seal barrels without causing the contents to ferment and to seal barrels with liquids not able to seal. Maybe by adding an item like yeast as a requirement for fermentation? Might reduce spoilage.
Allowing players to pick up sealed barrels. Holding a sealed barrel would require an empty "backpack slot", similar to holding a populated skep.
A Barrel tap item to be installed onto a barrel, allowing the player to extract fluids from a sealed(that isn't fermenting), but not allow adding fluids.