In a large pot, combine the milk, cream and salt.

Turn heat on low, and slowly heat the mixture until warm but can still be comfortably touched with a fingertip.

Add in the buttermilk, and stirring constantly, continue to cook the mixture.

As you stir, clumps of ricotta will start forming and floating to the surface.

When it starts to boil, add in the cold water and continue to stir. More ricotta will keep forming.

After the mixture has been vigorously boiling for a few minutes, turn the heat down even lower and you can start transferring the ricotta to a strainer.

Prepare a fine-mesh strainer with 2-3 layers of cheesecloth, and set it over a large bowl. As the mixture is still heating, carefully ladle the ricotta out of the pot and into the strainer. Repeat until all the ricotta is out. If you have a small strainer, you may need to use two.

Allow ricotta to drain for 10 min, then transfer to a serving platter or container with lid. It is fine if it's still a bit soft and leaks a bit more water.

Ricotta will keep in a tight-lidded container in the fridge for up to 8-10 days. It will progressively become drier as the days pass.