Step #1 Combine the milk & buttermilk in a heavy pot over low heat/flame.
Step #2 Place a thermometer in the liquid, without allowing it to touch the bottom of the pan, & continue to heat until the liquid reaches 175°.
Step #3 While the liquid is heating, rinse some cheesecloth & use it to line a strainer or small colander placed in a bowl, or line it with paper towels & it will work as well.
Step #4 When the ricotta forms on the surface of the milk (be patient--it may take a while), remove it with a slotted spoon or skimmer & place it in the lined strainer.
Step #5 Let the ricotta drain in the cheesecloth for 1 hr.
Step #6 Then place the lined strainer in a bowl & place this in the refrigerator to let drain for a few more hrs.