Instructions: 
Preheat oven to 110 degrees. Combine 1 cup of the milk and the nonfat dry milk in a small bowl; stir until the dry milk is dissolved. Pour the remaining milk into a saucepan; stir in the dry milk mixture. Heat the milk mixture slowly over low heat to 190 to 210 degrees. Remove from heat and cool to 110 degrees. Remove the protein film from the top and discard. In a small bowl stir the yogurt until smooth; stir in about 1/3 cup of the warm milk mixture until well combined. Add the yogurt mixture to the remaining milk in the saucepan. Stir well. Pour into one large container or smaller individual containers, leaving about 1/2 inch at the top. Cover and incubate 3 to 4 hours at a constant 110 degrees temperature in a preheated oven. Do not disturb. After 3 hours, gently shake to see if the yogurt is firm. If not, let stand another hour or longer. Refrigerate at least 6 hours before serving.  

Quantity: 
Makes 4 cups