Greek yogurt is a delicious dairy product that’s produced by taking regular yogurt and straining it to a delicious, protein-rich thickness. The thing is, though, all of that straining means that you’re straining something out of the yogurt. That something is more than water: it’s post-fermentation liquid called acid whey. For every three or four ounces of milk that enter a yogurt plant, one ounce of acid whey leaves. They can’t dump it in sewage systems or waterways, and at least one manufacturer actually pays local farmers to take the liquid whey away and do something with it.
Americans are crazy for Greek yogurt. Thicker than the yogurts we’re used to, the dairy treats come in pre-flavored and unflavored versions, and it seems like every dairy brand and grocery chain has their own version. Not all Greek yogurts are made in the same way, though. The normal method is to make yogurt, then strain the additional liquid whey, producing a denser product. This results in a product with about twice the protein of regular yogurt, but less calcium. That’s what most consumers probably picture when they pick up a container of Greek yogurt off the shelf. The huge demand for the products means that some manufacturers are finding other ways to get that thick texture and high protein content.