- 3/4 cup plain yogurt, preferably Greek-style, with live cultures
- 1 quart whole milk
- 1 quart half-and-half
- 1 pint heavy whipping cream (optional)
- On a work surface, lay four clean cotton towels in a cross pattern, each with one end overlapping a few inches in the center. Position a large baking dish or glass mixing bowl in the center of the towels.
- Set the plain yogurt on the counter to warm to room temperature while preparing milk mixture.
- Combine milk and half-and-half in a large, heavy, non-aluminum pot. Heat over low to moderate heat, stirring constantly, until mixture just comes to the boil. Immediately remove from heat and pour mixture into the waiting bowl. Add 1 pint whipping cream, if desired, for added richness.
- Allow mixture to cool to 112 degrees F (44 degrees C). Gradually pour 1 cup of the warm milk into the yogurt, whisking constantly. Return the yogurt-milk mixture to the bowl and stir well. Cover bowl with plastic wrap; wrap kitchen towels up and over bowl, covering completely. Let stand at room temperature until firmly set, 8 to 12 hours.
- Refrigerate yogurt several hours or overnight to chill completely.