Seth Rogen has explained the challenge of playing two characters who act opposite each other in his new movie.

The actor takes on dual roles in the comedy An American Pickle, about a factory worker in 1919 who falls into a vat of pickles and is accidentally brined for 100 years before he is discovered and emerges in present-day Brooklyn to find his great-grandson is his only surviving relative.

Rogen plays both Herschel Rosenbaum, who is devastated to learn his wife and child are long dead, and his great-grandson Ben, who cannot relate to his ancestor’s old-fashioned values.

He told the PA news agency: “We shot the movie really weirdly in that we did all of the Herschel stuff and then I shaved and then we went back and did all of the Ben stuff.

“Herschel is driving a lot of the scenes and I had a guy, Ian, who I was acting with who was my body double but it actually worked really well because Herschel is not that reactionary anyway, he’s kind of ploughing forward like a bull in a china shop.

“So as Herschel I was kind of allowed to drive the scenes and then when I was Ben I could listen to my own performance and react to it.

“It was a weird challenge, especially in the scenes that are very physical. I had these beeps in my ears that would cue me to do things so I was hearing my own dialogue in an earwig, coupled with several series of beeps, which would signify me to do something. Like beep beep beep, pick up glass.”

But for all the acting challenges, Rogen said he deeply related to the script, based on Simon Rich’s 2013 New Yorker novella Sell Out, about generational differences.

He said: “The story I could not have related to more, honestly. The first conversation me and Simon had about it, one of those things that hooked me was, he said ‘I have this picture of my great-grandfather on my desk when he’s in his mid 20s and I’m in my mid 20s looking at it and I couldn’t help but think that if we were alive and were the same age, he would hate me’, and I couldn’t relate to that more.

“I knew my grandparents my whole life until they passed away, my grandfather was in the navy and he played football, he was a plumber and had no patience for my bullshit.”

Rogen said he also responded to the disparities over attitudes to religion and faith, saying: “It’s something that was highly relatable and something I pushed hard to weave more and more into the fabric of the movie and it’s kind of an arc I’ve personally taken.

Rogen in the dual roles (Hopper Stone/Warner Bros/PA)

“I went to Hebrew school and I think like most people their instinct is to rebel against everything they were taught when they were a child.

“And then I sort of got over it and I’ve really actually found that there is a lot of very useful practical elements to Judaism, even if from a religious standpoint I don’t necessarily believe in the specifics of it, from an applicable cultural standpoint I see it’s benefits and around death and grief especially.

“And that is something that is a big theme in the movie, so to me that was a really interesting subject to delve into, how we at times throw the baby out with the bath water as far as our culture and upbringing goes, and how there are essentially useful tools tied into religions, as frustrating as that might be.”

An American Pickle is out now in UK cinemas.