Heat the milk to 80 or 90 degrees and stir for 2 minutes. Add the buttermilk and stir for 2 minutes. Mash the rennet and mix with about a tablespoon of water; stir for 2 minutes. The mixture should be tepid, comfortable to the touch. Set container aside and if you must cover, use cheesecloth to allow for air. Cheese will form curds in 24 to 30 hours. Place the curds in the molds and allow dripping for 8 to 10 hours. Add a splash of half-and-half when serving.