Butter is the story of an orphan named Destiny. At the age of ten she is placed with two parents Ethan and Jill Emmet. Ethan and Jill take Destiny to visit the Iowa State Fair. After arriving at the fair, Destiny goes off by herself. She finds the butter exhibit and takes a try. She soon discovers that she has a talent of sculpting butter. Bob Pickler, the man who created the butter sculpt, is very impressed with the level of talent that Destiny has.
Because Bob has won the sculpting contest so much, he is no longer allowed to compete. Laura, Bob's wife, has taken so much pride in his winning title, that she becomes very upset at this news. She goes to the house of the competition organizer in order to try to fight for the right for Bob to sculpt his butter. While Laura is at the organizer's house, Bob goes off to a local strip club. He meets Brooke, a stripper at the club.
Because she cares about the social status of the title, Laura decides that she will enter the contest herself. Little does she know that Destiny is also going to enter. Brooke also decides to enter because she wants to bother Laura and Bob, who owe her $600. They all participate and Laura comes in second to Destiny.
It is time for the state fair and Laura must compete with Destiny in the final round. Laura's butter creation is an exact replica of John F. Kennedy's personal car right after the assassination. The sculpture even features Kennedy's skull blown to pieces along with Jackie Kennedy and Clint Hill trying to escape the car. Destiny's creation is her biological mother in a rocking chair, holding a baby. Even though there is chaos before the final judging, Destiny still manages to win the prize, along with an offer to be officially adopted by the Emmets.