It is amazing that people still get excited about yogurt, considering that it has been around since 6000 B.C., when Neolithic herdsmen discovered that storing milk in animal skin containers curdled the liquid, thickening it and giving it tart flavor. But judging from the supermarket shelf space and commercial airtime now devoted to the latest iteration — thick and creamy Greek-style yogurt — interest in this ancient dairy product has never been stronger.
These days, yogurt is made not in animal skin containers, but in sterile metal vats. Here, milk is mixed with acidophilus, a healthy bacterial culture. The bacteria feed on the sugars in the milk, producing lactic acid, which gives yogurt its characteristically tangy flavor. An extra step is required to make Greek yogurt. Before it is packaged, it is strained to remove the liquid whey, giving it a less watery consistency than American-style yogurt. As a result, it is more concentrated and contains more protein than American-style yogurt.
It takes 64 ounces of milk to produce 16 ounces of Greek yogurt, more than twice as much as what goes into American-style yogurt. It’s not the most economical use of milk, and one reason why Greek yogurt is so expensive.
If this is the kind of thing that keeps you up at night, you can make your own Greek yogurt and repurpose the whey. Line a strainer with cheesecloth and set it over a bowl. Then, dump plain American-style yogurt into the strainer and let the excess liquid drip into the bowl. After a few hours, you will have thick, creamy, and extra-nutritious Greek yogurt. Use the cloudy liquid that has collected in the bottom of the bowl in a favorite bread dough recipe. Its milk sugars will give your bread a very mild sweetness and beautiful golden color.
For the baker, Greek yogurt comes in handy for adding richness and flavor without a lot of fat. Swap it for an equal amount of sour cream, mayonnaise or cream cheese in cake, muffin and quick bread recipes.