Fact: Greek yogurt is so hot right now. You know it, Jamie Lee Curtis knows it, John Stamos knows it. But Greek yogurt has a dark side: Making it produces acid whey, and acid whey is a huge fucking problem.
Acid whey is, as Modern Farmer reports, "a thin, runny waste product that can’t simply be dumped." Um, ew. Why?
Not only would that be illegal, but whey decomposition is toxic to the natural environment, robbing oxygen from streams and rivers. That could turn a waterway into what one expert calls a “dead sea,” destroying aquatic life over potentially large areas. Spills of cheese whey, a cousin of Greek yogurt whey, have killed tens of thousands of fish around the country in recent years.
Yikes. To be clear, this is not a yogurt problem, this is a Greek yogurt problem.
Unlike traditional yogurt, Greek yogurt is strained after cultures have been added to milk. In home kitchens, this can be done with a cloth. Greek yogurt companies still throw around the term “strained,” but in reality industrial operations typically remove the whey with mechanical separators that use centrifugal force.
The resulting whey is roughly as acidic as orange juice. It’s almost entirely made up of water, but scientists studying the whey say it contains five to eight percent other materials: mostly lactose, or milk sugar; some minerals; and a very small amount of proteins.
Some companies — including Chobani — are so desperate to get rid of acid whey that they'll pay farmers to take it. One farmer, Neil Rejman, mixes the acid whey in with his cow feed, but he can't use too much or everything turns liquidy and gross; "like dropping water on your pizza,” he says.
The good news is that there has been a yogurt summit (!) and our nation's finest Dairy Experts are hoping to solve the acid whey issue. Some options (besides cow feed) include extracting the protein for infant formula and converting the whey's lactose into methane that can generate electricity.
But we'd better come up with something quick: Greek yogurt is a $2 billion market and total yogurt production in New York has tripled since 2007. Picture acid whey spreading from town to town, eating everything in its path, like The Blob. As Modern Farmer's Justin Elliot writes, "the tidal wave of acid whey is not slowing down."
Whey Too Much: Greek Yogurt's Dark Side [Modern Farmer]