Barrels were used by the Elves of Mirkwood to ship items such as apples, wine, and many other foods. They were shipped back to their origin when emptied via a brook that ran down the middle of the Mirkwood Elves' fortress, where they were pushed into the brook via a portcullis, and then finally float along the Forest River.
Barrels are only mentioned in The Hobbit, when Bilbo Baggins freed the Dwarves from the dungeons by using the Ring to open up the locks of the cells that held the twelve dwarves while the elves enjoyed a feast. He went, still wearing the Ring, and found twelve barrels, put some straw in them, and sealed them up. Then the elves pushed the barrels, which they believe to be empty, into the brook. Bilbo, being unable to go into a barrel himself, grabbed onto the last barrel and held on the bottom, using it as a "life ring". Later, he pulled over another barrel and used the two barrels as a raft. After a meal, the barrels were tied up into a raft, pushed by elves and finally end up near Esgaroth, where they were hauled back to shore by men. At this point, the barrels containing the dwarves were opened by Bilbo. Thorin, Fíli and Kíli and many of the dwarves took a while to get back to normal, due to slightly leaky barrels and lack of air. A number seemed only half alive.
- "I do not wish to see apples again, after smelling them in my barrel the whole way.": Fíli
- "Well, here we are!": Thorin after the raft-ride