When you’re getting ready to watch “An American Pickle,” the new Seth Rogen movie now available on HBO Max, it’s best to curb any instinctive criticisms such as, “I don’t think the Yiddish is quite right,” “How does a factory in Brooklyn go completely untouched for 100 years?” “That’s not how you use a SodaStream!” and, of course, “Human preservation by pickle brine has been scientifically disproven.”

In this very Jewish whimsical comedy, Herschel Greenbaum (Rogen), formerly a ditch digger in the shtetl of Schlupsk, lives in New York with his pregnant wife and squashes rats at a local pickle factory. After a skirmish with some rodents of unusual size, he plunges into a vat of pickles that is immediately sealed and then abandoned with the rest of the factory. A century later, Herschel emerges not having aged a day; scientists explain that he was preserved perfectly by the brine, and everyone agrees their explanation makes perfect sense. He is matched via DNA with his only living relative, his great-grandson Ben Greenbaum (also played by Rogen).

The film is set in contemporary times, but it contains a fair amount of magical realism. Herschel and Ben Greenbaum are family members with deep differences, navigating conflict between old and new worlds. They may look alike, but they look at the world very differently.

Herschel fresh out of brine is a man out of time: Everything he knows is gone, and he is judgmental about everything he encounters. Ben is a loner living in Brooklyn, a struggling web developer who’s spent years trying to get his app — which rates how ethical various products and businesses are — ready to pitch to investors. Herschel engages in some gleeful, mad scientist pickle concocting, creating a product that hipsters discover and elevate as a trend replete with a robust social media following.

As the rift grows between Herschel and Ben, the two become enemies, each powered by anger, guilt and grief.

The film includes shtetl echoes of Tevye and Anatevka, pokes fun at Brooklyn hipsters, and imagines how someone who “Rip Van Winkled” their way into the 21st century might be embraced by social media as a quirky new flavor and then canceled, also via social media, for speaking his antiquated and unfiltered truths.

Rogen, playing the dual roles, experiments with the differences and familial similarities between the two characters. Herschel has shtetl superstrength that helps him “do violence,” while Ben is passive and just gets injured. In Ben’s dancing we see modern influences, but in Herschel’s there’s a more subtle, Tevye-ish foot-stomping familiar to “Fiddler” fans. While Herschel once dreamed of being wealthy enough to try seltzer, Ben has his own SodaStream — his great-grandfather’s American Dream fulfilled in delightful, on-demand effervescence.

With such a strong family resemblance, each character can see himself in the other. But the generational gap between them is vast — possibly impassable — as the film considers whether younger, American-born generations can ever live up to the narratives, biases and experiences of their immigrant ancestors, and how they can forge a contemporary identity while balancing the expectations of family members who demand modern achievement while keeping ties to tradition, the Old Country and religious beliefs.

Based on a four-part New Yorker novella by Simon Rich and filmed in Pittsburgh, coincidentally around the time of the Tree of Life shooting in 2018, “An American Pickle” contains an undercurrent of pain, grief and questioning of faith. Herschel’s pain is always accessible. “You must tell me everything of [your parents’] death so I may bear witness to your grief,” Herschel commands Ben. But Ben denies his grief any space in his life — he puts his memories in a closet and will not discuss them.

Ben can understand why someone like Herschel is religious. “That makes sense for someone from your era,” he says. Herschel is appalled by Ben’s rejection of faith, observance and community, all of which he considers essential.

Whatever your connection to faith, grief or family, there’s something for everyone in “An American Pickle,” especially those of us with Eastern European ancestry or other immigrant backgrounds. To complete your viewing experience, make sure to have the right refreshments: Crack open a fresh jar of pickles (or be like Herschel and make your own using “reclaimed” dumpster cucumbers, salt and reusable jars). Pause while you enjoy a crisp glass of seltzer and really feel the magic of each carbonated bubble. And know that although your great-grandparents may ever have imagined the life you have now, they would be proud.