To the yang of every superhero’s rise, there is the yin of an equally formidable foe. Batman and the Joker, Spiderman and the Green Goblin, and in the fermented dairy aisle, Greek yogurt and acid whey.

Greek yogurt’s decade of protein-powered growth in American refrigerators has been hounded by stories of the production of “toxic” acid whey and its potentially nefarious impact on the environment. But is acid whey really the villain it’s been made out to be? Or is it just misunderstood?

Understand the enemy

Acid whey’s bad rap starts with its name, which makes it sound like a spill would burn a hole through the floor. But when it comes to food, is it really deserving of its acidic moniker?

Coming in at a pH of 4.5 to 4.2, acid whey’s acidity compares to beer. Juices, ciders, wines and kombucha are actually much more acidic, below 4.0.

The acidity does have ramifications for some processing such as drying, but the lower pH also means that many of those important dairy minerals have solubilized; thus, acid whey is rich in calcium, magnesium and phosphorus.

Due to the extended pasteurization in Greek yogurt production — which denatures whey protein, trapping it in the casein gel — acid whey has very little protein. But it is high in lactose, a valuable carbohydrate. You see, young Skywalker, there is still good in acid whey.

Acid whey is typically loaded into a tanker and hauled off for use as a mineral additive to soil, a nutritional component for animal feed or an energy substrate for anaerobic digesters. This inherently involves the environmentally unfriendly transport of a lot of water. 

Membrane filtration technologies have come to the rescue, allowing for the concentration of acid whey to minimize the carbon footprint of transportation. Membrane technologies haven’t stopped there; researchers at universities across the country have been optimizing and cascading these technologies to tease out each of the components in acid whey — lactose, minerals and lactic acid — so their value can be captured and put to good use.

Toast a hero

Lifting a glass of whey for an afternoon recharge has never been popular in the United States, but whey-based products have gained traction in Europe. There are plenty of signs that the American taste palate is changing, too. Growth in beverages such as kombucha, vinegar tonics and switchel show rising interest in sour good-for-you propositions, where acid whey could naturally find a home. 

We are beginning to see action here. White Moustache, an artisanal strained-yogurt producer in Brooklyn, has a line of probiotic tonics and just launched popsicles from its acid whey. Perhaps all acid whey will need is a new superhero package and creation story.

I’ve heard stories of Dr. Kosikowski’s whey wine, but sometimes great ideas are too early for their times. Forty years later, we are beginning to see whey-based vodkas hit the global market, including those from Black Cow in the U.K. and the Hartshorn Distillery in Australia. Universities are also researching whey-based distilled spirits, and my lab is exploring acid whey-based sour beers.

In this era of new environmentally focused, health-conscious dairy consumers, the upcycling of acid whey represents a natural frontier. Rather than a “toxic” poison, it’s full of bioavailable minerals and potential prebiotic and probiotic components. Perhaps it’s the magic elixir for creating a new superhero in your portfolio.