It is amazing that people still get excited about yogurt, considering it has been around since 6000 BC, 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. Analysts estimate that one in three Americans eat yogurt regularly.
There are a lot of reasons yogurt has been beloved since the time of the woolly mammoth. First of all, it tastes great. Like other fermented foods, including cheese, sourdough bread and pickles, yogurt has a tangy flavor many people enjoy.
Then, of course, there are the health benefits of eating yogurt. Yogurt contains enzymes that help with absorbing nutrients. It also contains healthy bacteria linked to a strong immune system. And it is brimming with other good things: protein, calcium, B vitamins and minerals, including zinc, potassium and phosphorus.
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 also contains less naturally occuring sugar, since the sugar drains away with the whey.
Consumers and nutritionists love Greek yogurt, but not all environmentalists do. 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 Greek yogurt is so expensive. So far, manufacturers have not figured out how to use the large volume of strained whey that is a byproduct of the process. And disposing of it is a problem. Whey can't simply be poured down the drain. Its high sugar content would encourage an epidemic of sugar-eating bacteria in our waterways. So the whey must be treated to remove the sugar before it is dumped. The more Greek yogurt we eat, the bigger the whey problem gets.
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 recipe. Its milk sugars will give the 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, and you will get a significantly lighter result with no loss of quality. I used a cup of Greek yogurt instead of sour cream in a one-bowl cake recipe. I got a moist, sturdy, tasty cake that is good for snacking or for brunch when served with fruit and more yogurt on the side.
GREEK YOGURT CAKE
To decorate the cake, I raided my children's arts and crafts cabinet, which contains a book of silicone stencils that they use to make posters and decorate T-shirts. I placed a stencil on top of the cake, sifted some powdered sugar over it, and then carefully lifted it off. If you'd like a lacy effect, a paper doily will serve the same purpose.
2 cups unbleached all-purpose flour
1 1/4 cups sugar
1 teaspoon baking powder
1/4 teaspoon baking soda
1/4 teaspoon salt
1 cup plain low-fat Greek-style yogurt
1/4 cup low-fat milk
1/3 cup vegetable oil
2 large eggs
2 teaspoons pure vanilla extract
1. Preheat oven to 350 degrees. Spray a 9-inch round cake pan with nonstick cooking spray and dust with flour, knocking out any extra. Whisk together flour, sugar, baking powder, baking soda, and salt in a large mixing bowl. Whisk together yogurt, milk, oil, eggs and vanilla in a small bowl. Pour yogurt mixture into flour mixture and stir until just moistened.
2. Scrape batter into prepared pan and bake until golden and toothpick inserted into center is clean, 35 to 40 minutes.
3. Let cake cool in pan for about 5 minutes, invert onto a wire rack, then re-invert on another rack to cool completely. Dust with confectioners' sugar, slice and serve.
Makes 8 servings.