When people mention Greek yogurt these days, they’re not always talking about yogurt that came from Greece. But back when the term first caught on, they were.
In the early 1980s, Greece-based yogurt company FAGE started selling its wares abroad in the UK before expanding to the U.S. in the late 1990s. FAGE’s yogurt became so popular that non-Greek manufacturers began selling their own similar products, which were also called “Greek yogurt.”
What sets FAGE and other Greek yogurts apart from regular yogurt is a pivotal extra step in the production process. As The Kitchn explains, both types are a combination of milk and live bacterial cultures. You heat the milk to a specific temperature, insert the cultures, and then let the concoction ferment and firm up over time. Once that’s finished, you’ve successfully made yogurt.
If you want to turn it into Greek yogurt, you then have to strain out the liquid whey, a protein found in milk. (For this reason, Greek yogurt is known as straggisto in Greece, derived from the Greek word for strained.) Because you’re removing all that excess liquid, you’re left with a significantly thicker yogurt—and that thickness means that the remaining protein (and fat) is much more highly concentrated than it is in regular yogurt. According to Mother Jones, some of milk’s lactose ends up getting strained out, too, so Greek yogurt is also slightly lower in sugar.
In short, Greek yogurt is naturally thicker and higher in protein than its watery counterpart. That said, just because a cup is labeled “Greek yogurt” doesn’t automatically mean it matches that description. Though the FDA regulates yogurt, it doesn’t have any standards for Greek yogurt in particular; so manufacturers are free to use thickening agents, artificial flavoring, refined sugars, and other additives, and still call the result “Greek yogurt.”
Those additives aren’t necessarily bad: A given yogurt might be enriched with vitamins, for example, or sweetened with real fruit. But if you pick a so-called “Greek yogurt” off the shelf because you’re assuming it’s healthier than your go-to regular yogurt, be sure to check the ingredient list before you buy it.