Seth Rogen spent 10 months growing a beard for his movie 'An American Pickle' to shoot a 15-second scene

• Seth Rogen told Insider that he really grew out his beard for "An American Pickle."
• He did it because he says he hates how fake beards look in movies.
• Rogen plays two characters in the movie. He said he spent months growing out his beard to play the character Herschel, and then shaved and filmed all his scenes as Ben.
• But then he says they came up with an idea for another scene with Herschel after filming ended.
• Rogen spent another 10 months growing his beard again and filmed the scene, which was only 15 seconds long.

You can never say Seth Rogen isn't dedicated to his craft.

When the actor decided to do the movie "An American Pickle," in which he plays an immigrant from the 1920s who is trapped in a pickle vat for 100 years and now lives in modern-day Brooklyn (he also plays the character's only surviving relative), Rogen did not hesitate to physically transform into that character.

Meaning he grew a really big beard for the role.

"It's complicated to make a movie when somebody plays two roles, and we further complicated it by deciding that I was not going to wear a fake beard at any point of it," Rogen told Insider. "I think they don't look good, it's really as simple as that."

So that meant before shooting could start, everyone had to wait for Rogen to grow a bushy beard.

The actor said it took months to grow and then they went and filmed all the scenes of Rogen playing Herschel Greenbaum, a 1920s-era Eastern European Jewish immigrant who — thanks to the magical preserving powers of pickle brine — is now living in 2020.

Rogen then shaved the beard and shot all the scenes as Ben Greenbaum, Herschel's modern-day relative who helps him get acclimated with 21st-century life.

But then a big curveball was thrown into the process after principal photography ended.

"We thought of one 15-second thing that we wanted to shoot and I grew a beard for 10 months in order to shoot that thing," Rogen said.

"The amount of money and time and conversations and thoughtfulness we had to give to that beard, it wasn't like he grew the beard and it was cool, every now and then he would be like, 'I can't f---ing take this anymore, I want this off,'" Rogen's writing and producing partner Evan Goldberg told Insider.

Rogen admitted that a "big beard is unruly."

"This is a more comfortable level for me," noting to his currently trimmed beard.

Rogen's "An American Pickle" is available on HBO Max on Thursday with an HBO Max subscription. You can sign up here for $14.99 per month. (When you subscribe to a service through our links, we may earn money from our affiliate partners.)