LOS ANGELES — A federal appeals court reinstated California’s ban on foie gras Friday, finding that a state law preventing sales of the luxury liver pate made by force-feeding ducks and geese was not pre-empted by federal authority to regulate poultry products.

The ban was passed more than a decade ago after proponents said the process of fattening the livers of the birds was cruel and inhumane. The law took effect in 2011, but was blocked by a court in 2015, delighting chefs who wanted to serve the delicacy and leading to protests by animal rights groups.

While the unanimous decision by three judges won’t immediately take effect, giving farmers and a restaurant time to seek further review, animal activists celebrated.

“The champagne corks are popping,” said David Perle of the People for the Ethical Treatment of Animals. “PETA has protested against this practice for years, showing videos of geese being force-fed that no one but the most callous chefs could stomach and revealing that foie gras is torture on toast.”

State lawmakers voted in 2004 to bar California farmers from force-feeding birds with a tube, which is how foie gras, is produced. That part of the law, phased in over seven years, was not challenged.

But foie gras farmers in Canada and New York and Hot’s Kitchen in Hermosa Beach targeted a second part of the law that banned foie gras produced out of state from being served in restaurants or sold in markets.

They argued successfully in the lower court that state law was superseded by the federal Poultry Products Inspection Act. That law prevents states from imposing labeling, packaging or ingredient requirements different from federal standards.

The main question was whether the state was banning an ingredient or a process.

“It is not the livers that are force-fed, it is the birds,” Judge Jacqueline Nguyen of the appeals court wrote. “The difference between foie gras produced with force-fed birds and foie gras produced with non-force-fed birds is not one of ingredient. Rather, the difference is in the treatment of the birds while alive.”

A lawyer for the farmers and Hot’s Kitchen said the fight was far from over.

“The ruling is disappointing, the reasoning is flawed,” attorney Michael Tenenbaum said. “Federal law is supreme when it comes to poultry products, whether it’s foie gras or frozen chicken breasts.”

When he won in U.S. District Court two years ago, Tenenbaum sent a press release saying that chef Sean Chaney was shouting “let the foie gras start flowing” from the rooftop of Hot’s.

Chaney said he plans to continue serving the rich treat until ordered to stop by a court and said the ruling was merely “a little speed bump.”

While the popularity has waned since they were allowed to first serve it after the lower court ruling, there are still popular selections on a special menu customers must request, Chaney said.

Among the offerings are “Lego my foie,” a waffle with a dollop of pate and maple syrup and a burger topped with the spread.

He plans to put foie gras back on his main menu this fall despite the ruling.

Tenenbaum said he would seek a review from a full panel of the 9th Circuit and press on to the Supreme Court if necessary.

If the appeals court rejects a review, the ruling will take effect after the case is returned to the lower court, where Tenenbaum can raise other issues.

David Levine, an expert in federal court procedure at the University of California, Hastings College of the Law, said it’s a longshot that the ban won’t go into effect.

“It’s probably the end of the road, but not tomorrow,” Levine said.

John Antczak in Los Angeles and Sudhin Thanawala in San Francisco contributed to this report.