Lerner Publishing Group, Minnesota’s largest book publisher and one of the nation’s top producers of educational books, is pushing more aggressively into the retail market with the purchase of Zest Books.

San Francisco-based Zest was a pioneer in young adult nonfiction, one of the fastest-growing segments of the book industry, and developed a solid sales record in bookstores. It has a reputation for eye-catching design and punchy titles, such as “Freshman: Tales of 9th Grade Obsessions, Revelations, and Other Nonsense” and “Death: An Oral History.”

Lerner, which publishes several hundred books a year under 14 divisions, aims at teens and young adults through its Twenty-First Century Books imprint that markets to schools and libraries. Its latest books cover topics such as global refugee flows, rape culture and minimalist living.

“We have a lot of great content in that imprint and we have been trying to figure out how to format and give it a slightly different voice to be able to sell it in the consumer market,” Adam Lerner, the company’s chief executive, said in an interview after the deal was announced last week.

In the acquisition, Zest founder and publisher Hallie Warshaw agreed to work with Lerner for at least a year to integrate the Zest imprint into Lerner’s portfolio and help reshape some of Lerner’s existing teen and young-adult titles to get into bookstores. “She really does know that voice,” Lerner said.

The Minneapolis firm will continue to publish and sell much of Zest’s existing catalog of books and may have authors and illustrators redo some of the books that have already been produced by Twenty-First Century. “We’ll also do a lot of new titles from both imprints,” Lerner said.

Warshaw, who studied at Rhode Island School of Design, was an illustrator for Scholastic in the early 2000s when sales of young adult fiction began to take off. She believed nonfiction books tailored for teens and young adults would also sell. After a stint as a designer at a tech company that moved her to San Francisco, she started Zest and published her first book in 2006.

“Many people who start publishing companies are editorially oriented. I’m a creative director. I’m coming from the design, visual side,” Warshaw said. “And my design sense was to just be very authentic and nonapologetic and get to the heart of the matter. That’s what all kids and people generally want.”

Her design background helped Zest make books that stand out on a shelf. “I have a good sense of what to put in a book, but everyone does judge a book by its cover,” she said.

In addition to history, current affairs and science topics, Zest produced books oriented around teenage life, getting through high school and college and getting started as an adult. “There was nobody writing life advice books for teens,” Warshaw said.

Lerner said the books being published for teens and young adults increasingly have taken on serious themes, in part because of the changes people that age have lived through.

“They grew up through the recession and many of them have experienced struggles in their home life,” Lerner said. “They’ve seen a lot of disruption in technology, identity and politics. They’ve seen a lot for how old they are. I think they’re less sheltered than millennials.”

Warshaw said one of Zest’s longest-running titles is a book on gender issues called “Queer.”

“It’s very steady because it’s on a topic that kids hear about and need to think about,” she said, adding a second edition is in the works.

She said she has identified several Lerner titles that she hopes to aim for the consumer market, including one on suicide. “They have tackled some hard stuff,” Warshaw said.

Zest’s publishing and production operations will be integrated into Lerner immediately, the executives said, and Lerner will take control of the warehousing and distribution of Zest’s books by the middle of next year.

Terms of the deal weren’t disclosed. Family-owned Lerner, which got its start in the early 1960s, has made several other acquisitions through the years. The company last year closed a bindery operation in Minneapolis.

Two children’s books from its Millbrook Press imprint, “Meet My Family: Animal Babies and Their Families” and “The Vast Wonder of the World,” were named to the Star Tribune’s holiday books list. Another, called “My Beijing: Four Stories of Everyday Wonder” was named to the New York Times list of notable children’s books for the 2018 holidays.