During the 2011-12 school year, Real Food for Kids, a Fairfax-based advocacy group, counted the replacement of additive-filled hamburgers on school lunch menus with 100 percent beef patties as one of its signature achievements.

“We worked so hard, and we talk a lot about this burger and how we changed it,” said JoAnne Hammermaster, co-founder and president of RFFK, as the group is known.

But this fall, Fairfax County Public Schools put a version of the old burgers back on the menu, citing complaints from students who said the all-beef patties didn’t look or taste right.

“To me, it was surprising because it seems a bit like a step backwards,” said school board member Ryan McElveen (At Large).

Hammermaster said the new burgers were offered to students in September without explanation or announcement. McElveen said that the change occurred after students noticed that the old patties appeared to be pink in the middle. In Fairfax schools’ kitchens, all hamburgers are precooked and then heated before being served. McElveen said it’s likely that the all-beef patties did not have a caramel coloring additive.

In a note to Real Food for Kids, Penny McConnell, Fairfax schools’ food and nutritional service director, wrote that “students are our customers and we listen to them and implement their requests if possible.”

The hamburger options in school lunchrooms long had been a target for RFFK. In a campaign to remove the 27-ingredient burger from the schools, Hammermaster frequently noted that McDonald’s burger patties have only three ingredients: 100 percent beef, salt and black pepper.

In the spring of 2012, Fairfax schools announced that the cafeterias would introduce a new all-beef burger. The news came after the school system acknowledged that the Don Lee Farms burgers that children ate contained an addition known as “pink slime,” a filler product officially called “lean finely textured beef.” It is a combination of beef scraps and connective tissue that is sprayed with ammonia gas to kill such pathogens as E. coli.

Fairfax schools spokesman John Torre said that the new patty does not contain pink slime.

Real Food for Kids hailed the change to all-beef patties. It was one of a string of recent victories for the organization, including a soda ban at seven Fairfax high schools and a fresh-food pilot program at George C. Marshall High School.

But without warning, Hammermaster said, the school system began serving a patty with 26 ingredients, also made by Don Lee Farms.

According to nutritional information, the new patties contain caramel coloring and other tongue-twisting additives and preservatives. Stored in freezers, the patties can last up to 12 months.

“If you look at a hamburger package and you can’t read the ingredients because you need a dictionary to understand it, something’s wrong,” Hammermaster said.

Torre said that cost was not a factor in the change — the all-beef burgers cost 39 cents a patty, while the new Don Lee Farms burgers cost 32 cents each.

McElveen said that the school system should move quickly to find a 100 percent beef alternative to the current offering.

“While FCPS is claiming that this does not have pink slime, it’s worrisome,” McElveen said. “What we’re serving is still safe but by no means ideal.”