1. Peter Ostrum, who played Charlie, hit puberty while making the movie. If you listen close, his voice is much higher in the beginning of the movie than it is at the end.
2. Ernst Ziegler, the actor who played Grandpa George, fought in World War I and was nearly blinded by poison gas. Because of this, a red light was used to show him which direction to look during filming.
3. Denise Nickerson, the actress who played Violet Beauregarde, didn’t want to pick her nose for the movie because she was fostering a crush on Peter Ostrum, the actor who played Charlie.
4. Willy Wonka and the Chocolate Factory was shot in Munich, Germany, but in order to find enough little people to play the Oompa Loompas, the production had to cast actors from outside of Germany. Because of this, most of the Oompa Loompas did not speak English.
5. All of the “candy” that was on set was fake. Unless an actor was actually eating a piece of candy, you can guarantee that it was fake candy. Even some of the Wonka Bars were made of wood.
6. The Chocolate River was very real, though. The river was made of 150,000 gallons of water, real chocolate and cream. Because it was real, it ended up smelling really bad by the end of filming.
7. Every wonder why the foam in the Wonka Wash scene looks kind of like the foam that comes out of a fire extinguisher? That’s because they used the foam that comes out of a fire extinguisher, which, it turns out, is a skin irritant. Many actors had to receive medical treatment after coming in contact with the Wonka Wash.
8. Willy Wonka and the Chocolate Factory is based off of the Roald Dahl book Charlie and the Chocolate Factory. While it seems as if the name change was unnecessary, there’s actually a specific reason for this.
The movie was financed by the Quaker Oats Company, which planned to tie in the movie to a new candy bar. The title was changed in order to support the tie-in. However, the candy bars melted too easily, even while still on the shelf, and so they were removed from the market.
9. But the name change was probably fine with author, Dahl, who allegedly hated the movie so much he refused allow any more versions of the movie to be made while he was alive. He also refused to give up the movie rights to the sequel, Charlie and the Great Glass Elevator.
Dahl refused to watch the movie. Reportedly, he once saw 15 minutes of the movie when he was staying at a hotel, then turned it off once he realized he was watching a movie of his own book.
10. Gene Wilder’s performance as Willy Wonka was so iconic it even inspired a meme. However, Dahlwould have preferred the role gone to Peter Sellers or Spike Milligan. Additionally, all six members of Monty Python were considered for the titular role, but at the time none of them were a big enough star outside of England to be able to draw an international audience.
Gene Wilder said he would only take the role of Willy Wonka if he were allowed to do a somersault after his cane gets stuck in the scene where he comes out of his factory. Why? Because from that moment on, nobody would be able to know if Willy Wonka was being truthful or not. And we’re glad he did because he made the movie.