As prices of U.S. beef continue to go up, the beef processing industry is witnessing the comeback of the filler known as "pink slime." More and more producers are using the finely textured beef in their products in order to cut costs, despite the fact that the ingredient was practically phased out of the market two years ago, according to the Wall Street Journal.

Finely textured beef is processed from scraps left after the animals have been butchered. In 2012, sales and use of pink slime were halted after a huge wave of protests on social media, following reports that revealed the way the substance was produced. Many people even questioned if it was legal to use such ingredient as a filler, despite the fact that its use had been approved by the U.S. Department of Agriculture.

According to the Wall Street Journal, one of the two major manufacturers of pink slime, Cargill Inc., is selling its product to about 400 customers, including retail stores and food-processing companies. In fact, this figure is higher than its customer numbers in 2012, although most buy smaller quantities, the newspaper pointed out.

The comeback of the ingredient is largely due to the unprecedentedly low cattle supply, which led to a 27 percent increase in retail prices of beef over the past two years. Although it is almost impossible to estimate what proportion of the currently sold hamburgers contain pink slime, both Cargill and the other major producer, Beef Products Inc., have confirmed that sales rates have been recovering, the news source said.