Barrels help with Spoilage. Reducing spoilage by 5% per active barrel. Some builds can have upto 10 Barrels.
Cellar may have inherent spoliage reduction but this has yet to been tested or confirmed.
![](http://static.miraheze.org/farthestfrontierwiki/thumb/8/8e/Barrels_in_Brick_Root_Cellar.png/300px-Barrels_in_Brick_Root_Cellar.png)
Barrles are not considered consumed when they are placed inside a building. They are considered used when the duriabilty has been reduced to 0%.
![](http://static.miraheze.org/farthestfrontierwiki/thumb/b/bc/Barrels_Produced_and_Consumed.png/300px-Barrels_Produced_and_Consumed.png)