How to Make It
Line a colander with a double layer of cheesecloth and set it over a large bowl. In a very large saucepan, combine the milk with the buttermilk and cream. Cook over moderate heat, stirring occasionally, until the milk starts to separate and reaches 185° on an instant-read thermometer, about 20 minutes. Remove the saucepan from the heat and let stand for 10 minutes. Using a ladle, gently spoon the mixture into the prepared colander and let drain at room temperature until the ricotta is thick, about 4 hours. Transfer the ricotta to a large bowl, season with salt and refrigerate; reserve the whey for another use.