Lay three layers of cheesecloth over a colander. Add the milk to a large heavy pot and place over medium-high heat. Stir in the lemon juice and salt and heat until an instant-read thermometer reaches 80°C. The milk will begin to just bubble and start to steam. At this temperature you'll begin to see the curds separate from the whey. Be mindful of over stirring the ricotta while the curds are forming, you don't want to make your ricotta stiff. Let it sit for 5 minutes undisturbed and you will be left with a very creamy and pleasant finished result.
Gently remove the curds from the pot to the colander. Use the side of the cheesecloth to very gently release some of the liquid. Tie up the curds using butcher's twine and let drain for 5 to 10 minutes.
Remove from the cheesecloth and place in a bowl. Serve warm on toasted bread with lemon zest and a drizzle of extra-virgin olive oil. Cook's Note: Refrigerate leftover ricotta in a covered container for up to 5 days.