Recycled Yogurt Waste is Loaded with Powerful Uses
In 2015, more than 770,000 metric tons of Greek yogurt were produced in the United States, representing nearly 40 percent of the domestic yogurt market. But did you know that for every ton of Greek Yogurt manufacturers produce, they also generate two or three tons of waste in the form of acid whey. A recent issue of Chemical & Engineering News (C&EN) looked at the interesting scientists are making use of this product that was previously considered waste.
Acid whey is the liquid by-product left over after yogurt has been strained or centrifuged to produce thick and creamy Greek yogurt. For years, companies paid farmers to spread the acid whey on land as fertilizer or to feed it to livestock. While it might seem good for farmers, if too much of the whey is spread on land, the mixture will run off into nearby waterways, leading to algal blooms, low levels of dissolved oxygen, and fish kills.
As demand for Greek yogurt ballooned, its makers started working with scientists to develop alternative uses for the whey. As a result, there are now more than 3,500 patents related to the use of yogurt acid whey, about 75 percent of which were published within the past five years. Many of them focus on methods for extracting valuable ingredients, such as proteins and lactose.
Yogurt makers are also investing in anaerobic digesters that rely on bacteria to break down the whey into methane for electricity, and scientists have found methods to turn yogurt acid whey into animal feed and industrial-grade ethanol. One food company has developed a product that can be used to incorporate acid whey back into dairy products, such as cream cheese, dips, and even yogurt.