There are plenty of good reasons why yogurt sales have increased by 40 percent over the past five years. High in protein and calcium, and a probiotic powerhouse (if it's got the live and active cultures label), yogurt is a magnificent food. Not only is yogurt simply delicious alone as a healthy snack or breakfast, it's also an extremely versatile cooking ingredient. It works as a lower-calorie and lower-saturated-fat replacement for cream, mayo, oil and sour cream in many recipes.

With so many varieties available in the store, I never thought I would make yogurt at home. But after trying it out it in the Test Kitchen, I'm a homemade-yogurt convert! Making yogurt at home is actually really easy. The best part: you save money and you can control the flavor, thickness and quality. Plus, if you want, you can strain it to make Greek-style yogurt. Now that's personalized yogurt!

To make your own yogurt, you'll need 4 cups of milk and 1/4 cup of plain, unsweetened yogurt with live and active cultures. Because you need a little bit of yogurt to make your own yogurt, pick a plain yogurt you like the taste of. My favorite yogurt to use as a starter is Noosa, an Australian-style yogurt from Colorado, because the flavor is tangy. I prefer to use reduced-fat, 2% milk because it creates creamier yogurt than skim milk and without as much saturated fat or as many calories as whole milk, but you can use any milk you have on hand. (I also pick organic milk from a local dairy.) You'll heat the milk to 180°F and then cool it to 110°F, stir in the yogurt and transfer it to two mason jars or a heatproof bowl and cover with a lid or plastic wrap. For the milk to transform into yogurt, it needs to incubate in a warm environment. Because I don't have a yogurt maker at home-and because I live in chilly Vermont-my oven serves as a warm spot: I just turn it to 200°F for 5 minutes and then switch it off. Then I place the loosely covered mason jars or bowl in the oven for 8 hours.

Recipe to Try: Homemade Plain Yogurt

After the milk has been magically transformed to yogurt after 8 hours, place the jars in the refrigerator until cold. If you prefer Greek yogurt, strain the yogurt through cheesecloth or in a Greek yogurt maker. The strained whey, the liquid left over from Greek yogurt, can be used like buttermilk.

To make more yogurt, don't forget to save at least 1/4 cup of the yogurt from your last batch. And trust me, you'll definitely want to!