SEOUL—Catching an early afternoon screening of “Dune,” Jang Yoo-mi showed up 30 minutes early. It wasn’t to watch the trailers or grab a better seat. She did it for the popcorn.

Under yearlong Covid-19 restrictions that lift Monday , Ms. Jang and other South Korean popcorn lovers have made an unusual sacrifice for the classic cinema snack. The multiplexes and their concession stands have stayed open, letting people chow down in the lobby. But inside the theater itself, eating has been banned.

Ms....

SEOUL—Catching an early afternoon screening of “Dune,” Jang Yoo-mi showed up 30 minutes early. It wasn’t to watch the trailers or grab a better seat. She did it for the popcorn.

Forbidden fruit

Under yearlong Covid-19 restrictions that lift Monday , Ms. Jang and other South Korean popcorn lovers have made an unusual sacrifice for the classic cinema snack. The multiplexes and their concession stands have stayed open, letting people chow down in the lobby. But inside the theater itself, eating has been banned.

Ms. Jang, a 33-year-old cafe worker, wolfed down half of her large-size tub of salty-and-caramel popcorn before handing over her ticket. To enter, she had to place a plastic lid atop the popcorn—and keep it there—for the entirety of the 155-minute film. She planned to save the leftovers.

“I can watch another Netflix movie at home eating the rest,” said Ms. Jang, in between bites.

The popcorn prohibition inside cinemas didn’t leave South Korean movie snackers all that salty. Instead, they adopted new habits to gorge on movie popcorn without the movie.

Popping the buttery snack fresh at home isn’t a habit that South Koreans ever quite picked up, with few stores stocking bags of kernels or microwavable bags. Ready-made versions are sold at convenience stores. But fresh batches largely remain the provenance of cineplexes.

One theater chain’s promotional event, promising to fill any container full with popcorn for about $5, drew tens of thousands of participants who lugged in laundry baskets, trash cans and ice boxes. Cineplexes saw a booming market for popcorn home delivery. Some dropped by for popcorn as if it were takeout food, skipping the movie altogether.

Others went rogue to circumvent the kernel crackdowns.

A woman buying popcorn at South Korea’s CGV theater.

Photo: Dasl Yoon/The Wall Street Journal

A few weeks ago, Kim Hye-in, a 20-year-old university student, bought a small-sized popcorn that she managed to sneak inside her hoodie on the way into the theater. It didn’t make sense to her that South Korea’s Covid restrictions barred movie munching but allowed soda sipping. She nonetheless took precautions for her protest indulgence, in case a nearby patron might report her rule-breaking.

“I chewed as quietly as I could,” said Ms. Kim, who managed to consume all her popcorn while watching “Venom: Let There Be Carnage.”

Covid restrictions in countries that took pride in taming the virus have remapped a range of quotidian activities. Only recently, after vaccination rollouts have hit key milestones, are the smaller signs of pre-pandemic living beginning to re-emerge, albeit with some caveats.

In Japan, hand dryers are back on in some public bathrooms, though not at many offices. Hong Kong hotel buffets have reopened, while outdoor barbecues are closed. Australian night clubs can operate, but patrons can’t dance.

Many movie theaters were forced to close during lockdowns and concessions alongside them. Global box office revenues fell more than 70% last year to $12 billion, according to the Motion Picture Association. World-wide movie popcorn sales tanked as well, though store-purchased varieties saw a significant uptick, according to market researcher Euromonitor International.

South Korea, which never completely shut down its cinemas, gave the thumbs up again to popcorn eating inside theaters after the country recently passed a 70% vaccination threshold. Health officials have regulated everything from treadmill speeds to the size of public protests. Starting Nov. 1, South Korea is relaxing those measures. Gyms, restaurants and cafes can open without limiting their hours. People will be allowed to eat inside baseball stadiums. Groups of up to 10 people will be allowed to gather.

Moviegoers sipping drinks in a theater lobby.

Photo: Dasl Yoon/The Wall Street Journal

CJ CGV Co.

, one of South Korea’s largest movie-theater operators, expects people will soon flock back, though is betting popcorn demand won’t spike to unusual levels, a spokeswoman said.

In May, CGV filled large cement bags with about four large-size servings of popcorn for about $8.50 apiece. “Any time, anywhere,” read the advertisement, which featured a shirtless young man pouring the snack on himself. The bags sold out within days.

A manager at rival Lotte Cinema, whose theater in Seoul has four popcorn makers, is more bullish. “We’re expecting them to empty out the way they did in 2019,” he said.

Song Mi-jin, a 43-year-old mother of two, has already booked tickets for a Monday showing of “Ron’s Gone Wrong,” a children’s film.

“I can only keep my kids quiet during a movie if they’re eating popcorn, so I haven’t been to a theater in a while,” Ms. Song said.

Lee Jin-seo, a 29-year-old office worker, said she has established a new weekend routine. She makes the 10-minute stroll from her apartment to a local movie theater, buys a large-size bucket and heads back home.

“There are no good movies to watch and I’d rather eat popcorn on my couch,” said Ms. Lee, who planned to scarf down the popcorn while binge watching the rest of “Squid Game,” the South Korean dystopian drama.

Byun Hee-jin, a 24-year-old university student, hasn’t given up on moviegoing, in part because she so dislikes the popcorn sold at convenience stores. Not hot or crunchy enough, she argues. Sitting in the lobby after finishing “Dune,” Ms. Byun realized she had struggled to focus on the sci-fi film’s plot because her mind kept drifting to the bucket of caramel popcorn in her lap. She worried if it had stayed fresh.

It hadn’t. But even cold movie popcorn was better than convenience-store fare, Ms. Byun said, before polishing off the last bits from the tub.

“I could smell my popcorn throughout the movie,” she said, “and could barely focus.”

Ahn Seong-jin, a 22-year-old university student, didn’t even get the luxury of enjoying the aroma from the salty snack during his showing of “Dune.” Having ordered a large-size bucket, Mr. Ahn assumed he’d be allowed to bring the popcorn inside the theater, and maybe even sneak in a bite or two. But theater staff demanded he leave the tub outside, next to a row of others. “I’ll come back to watch another movie next week,” Mr. Ahn said.

For others, new habits can die hard. Standing curbside hailing a taxi, Park So-yeon, a 32-year-old office worker, held a filled-to-the-brim tub of popcorn in her arms. “Some people stare at me for taking a fresh batch home,” Ms. Park said. That hasn’t stopped her so far, she said, and neither will the decision to lift the ban.

Write to Dasl Yoon at dasl.yoon@wsj.com