Only 33% of milk used to produce Greek yogurt and other strained dairy ends up in the finished product; the remaining two thirds is acid whey.
Acid whey has a lower pH (typically between 4 and 5) than sweet whey and is more difficult to process due to the levels of calcium, phosphorus, lactic and citric acid, and salts.
Discarding acid whey as waste is associated with environmental risk for dairy companies.
The dairy industry has long grappled with its acid whey problem. A high-volume by-product of yogurt and acid-coagulated cheese production, acid whey must be treated and neutralized before being discarded. Improper disposal is associated with environmental risks including algal blooms and depleted oxygen levels in waterways, which can threaten biodiversity and side-track dairy firms' sustainability efforts.
As a raw material, acid whey can be used used as a fertilizer; processed into biogas; and, to a limited extent, used as livestock feed. Dairy companies such as US Greek yogurt maker Chobani may leverage filtration systems to recover water from acid whey, or, like Yoplait maker General Mills, use anaerobic digesters to turn acid whey into biogas. Companies have also been looking at ways to recover proteins, lactose, minerals and organic acids for use in probiotics, fermented beverages, and other applications.
More recently, Arla Foods Ingredients, a division of Arla Foods, has come up with high-protein formulations based on using upcycled acid whey in shelf-stable dairy beverages.
The three concepts demonstrate the potential of acid whey for use in products with an ‘upcycled’ positioning, the company says. These are: an 8% protein drinking yoghurt with pineapple / coconut flavours; an 8% protein creamy dessert with pineapple / coconut flavours, and an 8% protein beverage with strawberry flavour.
In each recipe, acid whey accounts for between 50% and 73% of the full product and is combined with ingredients from the firm’s range of microparticulated whey proteins. Described as providing a mild dairy taste and smooth and creamy mouthfeel, the recipes can be produced on a standard dairy line and offer good viscosity control and stability through shelf life.
Upcycling acid whey as an ingredient in functional dairy products can both valorize a waste material while enabling brands to appeal to climate-conscious consumers.
“We’re seeing the high-protein trend in most markets and regions,” Barbara Jensen, Commercial Sustainability Manager, Arla Foods Ingredients, told us.
“Because it has driven demand for products such as Greek style yogurts, skyr and cottage cheese, one of its effects has been an increase in the volume of acid whey generated, creating a waste management challenge.
“This is most evident in the US and Europe, but the developing protein trend in countries like China and Saudi Arabia has also increased the need to find a sustainable way to use acid whey.”
Meanwhile, demand for products with an upcycled positioning has emerged as a trend in consumer behavior that offers a sustainable alternative to waste management, Jensen added.
“This shift has caught the attention of innovative manufacturers – brands that incorporate upcycling into their product offerings can market themselves as environmentally responsible, aligning with the values of eco-conscious consumers.”
Do consumers understand the concept of upcycling, however? “Consumers are interested in sustainable dairy options, but there’s still a huge value-action gap, meaning that only around 20% of them act on it,” Jensen said, citing Kantar Sustainability Sector Index 2023 data.
“Brands have started to incorporate upcycling positioning into their product offerings and market themselves as environmentally responsible, aligning with the values of eco-conscious consumers. However, the upcycled solutions currently available on the market mostly relate to the re-use of fruit materials that would otherwise have gone to waste. The re-use of acid whey is currently communicated in only a small number of cases.”
Using upcycled whey in a formulation doesn’t impact other label claims, such as ‘high in protein’, Jensen added.
“Dairy companies can continue to make the claims they are used to. For example, they can still make high-protein claims; they can also label products as ‘upcycled’ if they utilize ingredients that would otherwise go to waste, such as surplus milk or by-products from cheese production.
“In advertising and promotional content, companies can highlight their upcycling practices, emphasizing their commitment to sustainability.
“Furthermore, some third-party organizations offer certifications for upcycling, which can lend further credibility to claims – the Upcycled Food Association in the US is a good example. Of course, familiarity with local regulations regarding labeling and claims is essential to ensure compliance.”
This isn’t the first time that Arla Foods Ingredients has attempted to stimulate interest in upcycled acid whey applications. In 2016, the company launched an awareness campaign to promote acid whey’s use in dairy products, in combination with whey proteins.
At the time, the company’s Claus Andersen called acid whey ‘an untapped goldmine’ that is ‘often disposed of in waste streams or sold for little or no profit to farmers for use in animal feed’ when it could instead be converted into high-value consumer products.
There’s greater opportunity to achieve this in 2024 than 8 years ago, thanks to favorable consumer trends, he noted.
“Acid whey is nutrient-rich and in combination with the right ingredients can be used to create exciting new products that offer indulgence as well as nutritional value,” he explained.
“Allowing all the goodness of milk to be kept in the food chain is good for the planet, good for consumers and good for manufacturers, who can position products as upcycled, in line with a growing dairy industry trend.”
According to Circana, protien-related claims in the US grew 8.8% and saw $2.3bn in sales (Circana Core Outlets Total U.S. MULO+C – 52 Weeks Ending December 31, 2023). Meanwhile, the UK high-protein dairy sector recorded a 44.2% year-on-year growth in 2023 to reach a valuation of £117m, according to recent IRI data.