Photo: Liz Hafalia / The Chronicle 2014 Photo: Liz Hafalia / The Chronicle 2014

Sonoma County plant-based food company Miyoko’s Creamery filed a lawsuit against the California Department of Food and Agriculture Thursday on the grounds of freedom of speech.

In a December letter, the department told Miyoko’s it needed to stop using dairy words on its packaging and marketing materials. That included no longer calling its vegan spread “butter,” removing its “lactose free” claim and taking down a photo on the company’s website of a woman hugging a cow.

Miyoko’s CEO Miyoko Schinner said she found the letter “absurd” — particularly the part about the cow photo.

“What they’re trying to do is set a precedent that animals can only be viewed as food,” she said. “They can’t be viewed as pets or living beings that want to live lives of their own.”

In the lawsuit, Miyoko’s — along with the national nonprofit Animal Legal Defense Fund — argue that the Food and Agriculture Department’s mandates would violate the company’s First Amendment rights. Beyond her own business, Schinner said she decided to sue the department because these restrictions on packaging and marketing could negatively impact the plant-based food industry at large.

“We believe this will restrict the advancement of new and sustainable food systems,” she said. “California is supposed to be a progressive state that should be setting a gold standard for fighting climate change.”

The Food and Agriculture Department declined to comment.

Photo: Brett Stone

Michele Simon, executive director of the Plant-Based Foods Association trade organization, said she’s aware of “a handful” of other vegan companies in California that have received similar letters.

“California is really the home of innovation when it comes to the food movement,” she said. “It doesn’t make sense to have state regulators essentially hamstringing companies like this.”

This is not the first time a plant-based company has fought back against such regulations. Last year, Tofurky sued the state of Arkansas over a law prohibiting plant-based companies labeling their products as “meat.” Legislators argued the word “meat” would confuse consumers who might expect meat from an animal instead of a soy-based alternative. In December, a federal court blocked Arkansas from enforcing its law while Tofurky’s challenge proceeds.

Marcus Benedetti, owner of dairy company Clover Sonoma, said he appreciates the flexitarian movement — meaning people who eat mostly vegetarian but occasionally include meat and fish — but wants to make sure people understand the difference between plant-based dairy and real dairy. That’s where proper labeling comes in.

“By definition, all liquids produced by pressing or grinding plants are juices,” he said in a statement, referring to products like soy milk and almond milk. “None of these of these alternatives stand up to the naturally occurring nutritional profile of an 8-oz. glass of milk.”

Schinner started Miyoko’s in 2013 as an artisanal vegan creamery in Fairfax, making animal-free cheeses out of soaked cashews. Worried about the language on her labels amid tensions between the dairy milk and nondairy milk industries, she named her vegan cheeses “cultured nut products.” But consumers called them cheese anyway, and a few years later, she changed the labels to call them cheese, too.

With $6 million in funding, she later opened a larger facility in Petaluma. Now, she makes a variety of artisanal vegan cheese wheels — including ones aged in black ash and crusted with herbs de Provence — alongside cultured vegan butter, vegan mozzarella and vegan cream cheese. They’re sold in thousands of stores nationwide, including Whole Foods, Trader Joe’s and Raley’s.

If Miyoko’s Creamery doesn’t win its lawsuit against the Food and Agriculture Department and must change its packaging, Schinner said she plans to go the activist route and call her spread “They Say We Can’t Call it Butter.”

Janelle Bitker is a San Francisco Chronicle staff writer. Email: janelle.bitker@sfchronicle.com Twitter: @janellebitker