How to make ricotta cheese.
1) In a pot, combine three parts whole milk (not ultra-pasteurized) to one part buttermilk. Slowly heat to below a simmer. Stir in juice from one half lemon.
2) When the liquid loses opacity and gains a slightly yellow tinge, strain curds from the pot with a slotted spoon and place into a cheesecloth-lined colander. Salt to taste; you may also add fresh herbs or lemon zest.
3) Tie cheesecloth closed and hang in refrigerator over a pitcher. Hang for at least an hour (softer cheese) or up to four days (crumbly texture). Remove from cheesecloth, season to taste, and enjoy.