Heating the Milk
Pour the whole milk into a large pot and place it over medium heat. Heat the milk until it reaches approximately 185°F (85°C), stirring occasionally to prevent scorching. If you don’t have a thermometer, look for bubbles forming around the edges, but do not let it boil.
Curdling the Milk
Once the milk is hot, add the vinegar or lemon juice and gently stir for a few seconds. The milk should begin to curdle immediately. Let it sit undisturbed for 5–10 minutes to allow the curds to form fully.
Straining the Curds
Line a colander with a cheesecloth and place it over a large bowl to catch the whey. Carefully pour the curdled milk into the colander. Allow it to drain for 10–30 minutes, depending on the desired texture. For creamier ricotta, drain less; for firmer ricotta, let it sit longer.
Adding Salt