What is Pink Slime? What’s It Doing in Your Hamburger & Ground Beef

For the sheer number of burgers they consume—about 40 billion burgers a year—Americans could rename their country Burger Nation.

But how many Americans knew that for many years most of their burgers were not made from beef, but from an ammonia-treated burger extender product derisively dubbed by agriculture department officials as “pink slime”?

The good news is that—as quietly as they began using the product ten years ago, three fast food chains stopped using it last December.

McDonald’s, Taco Bell and Burger King stopped using the burger extenders made from lean beef trimmings treated with ammonium hydroxide, but the event hardly hogged the headlines.

Last December’s decision was reported by The ArgusLeader, a newspaper that reports in South Dakota, home of pink slime’s manufacturer, by a New York Times blog and by the United States meat industry. But other than that, few consumers even knew that they were eating the stuff for over a decade.

For many years, Beef Products Inc (BPI) boasted that “pink slime,” its hamburger filler product, was found in 70 percent of all hamburgers sold in the United States.

But after the fast food chains stopped using the products, business fell by 25 percent and the company is worried other chains and retailers will follow them.

And worried it should be: the company stands to lose big bucks. According to the New York Times, while Beef Products does not disclose its earnings, its reported pre-decision production of seven million pounds a week generated about US$440 million in annual revenue.

Pink slime: ‘innovative’ product?
For decades, “pink slime” was not seen as “yuck,” in fact, but as a bestseller product. It didn’t only corner two-thirds of the U.S. hamburger market but was even touted as an innovative “solution to the beef industry’s embarrassing food-borne-illness problem,” notes food writer Tom Philpott, now an investigative reporter for Mother Jones.

The U.S. meat industry has been plagued with food-borne illnesses for many decades and health and agriculture officials have continuously struggled to remove deadly E. coli, salmonella and other pathogens from hamburgers and other meat products.

As officials tussled with this problem, Beef Products came up with a novel idea in 2001: injecting beef with ammonia.

But not just only. The whole idea was to take parts of the beef previously thrown away or turned into low-value products into high-value hamburgers that were both cheaper and safer.

The company began to process beef trimmings by grinding them. These were then liquefied and the protein was extracted from the trimmings in a centrifuge, resulting in a lean product that was desirable to hamburger-makers. The resulting hamburger filler was then treated with ammonium hydroxide gas to kill E. coli , salmonella and the other dangerous microbes.

The product was marketed on three selling points, Philpott noted. “1) it’s really, really cheap; 2) unlike conventional ground beef, which routinely carries E. coli, etc., pink slime is sterilized by the addition of ammonia; and 3) it’s so full of ammonia that it will kill pathogens in the ground beef it’s mixed with.”

That year, the U.S. Food and Drug Administration signed off on the use of ammonia. Shortly after, officials at the Department of Agriculture went a step further: First, they endorsed the company’s ammonia treatment, saying it destroys E. coli “to an undetectable level.” Then, in 2007, when it began routine testing of meat used in hamburger sold to the general public, the U.S.D.A. exempted Beef Products, deciding that the ammonia treatment was so effective.

With the U.S.D.A.’s stamp of approval, pink slime became a mainstay in America’s hamburgers—without consumers even knowing it.