Smooth and creamy frozen yogurt doesn't need a fancy machine or other special equipment. You can enjoy this chilled treat with nothing more than a mixing bowl, a freezer and a little effort. Any type of yogurt works, whether plain or flavored. A low-fat yogurt results in a flavorful but less creamy dessert, while drained or Greek-style yogurt results in the creamiest of treats. You must plan ahead because it does take more time to make frozen yogurt without a machine.
Line a mesh colander with cheesecloth and set it over a bowl. Pour the yogurt into the lined colander and allow it to drain for 24 hours in the refrigerator if you prefer thick frozen yogurt. Use undrained yogurt if you prefer a lighter-textured frozen yogurt.
Slice any fruit additions into small pieces. For example, slice berries into halves or quarters, or slice peaches and larger fruits into 1/4-inch wide wedges. Toss the fruit with a small amount of lemon juice. Prepare up to 1 pound of fruit for every 1 cup of yogurt, depending on the intensity of fruit flavor you want.
Transfer the yogurt to a bowl and mix in up to 1/2 cup sugar per 1 quart of yogurt, depending on how sweet you'd like the yogurt and the sweetness of any additions. Stir in any additions, including the sliced fruit, if you're adding it. Chocolate chips, small candies or flavored syrups also make suitable additions. For vanilla yogurt, add up to 3 teaspoons vanilla extract for each 1 quart of yogurt. Mix by hand for chunky frozen yogurt, or blend with a mixer or blender if you want a perfectly smooth frozen yogurt.
Pour the mixture into a metal or plastic freezer-safe baking dish or casserole pan. Place the pan in the freezer for 45 minutes.
Remove the pan from the freezer and stir the yogurt mixture, breaking up any parts that are beginning to freeze. You can stir by hand or use a hand mixer. Continue to freeze the mixture in 30-minute increments, stirring thoroughly after each freeze cycle. It generally takes two to three hours and three to five stirring sessions before the frozen yogurt is ready to serve.
Defrost frozen yogurt at room temperature for 10 to 15 minutes before serving it if becomes too hard to scoop. If you don't mind alcohol in your frozen yogurt, stir in 3 tablespoons of vodka or spiced rum for each 1 quart of yogurt during the last freeze and stir cycle. The alcohol prevents the yogurt from freezing solid so it can stay smooth indefinitely.