Heat milk in a large pot over medium heat until it reaches 185°F (85°C). Stir occasionally to prevent scorching and use a thermometer for accuracy.

Remove from heat and stir in vinegar or lemon juice. Gently stir just once or twice to combine, then stop to allow curds to form undisturbed.

Let sit for 10 minutes until curds form. The mixture should separate clearly into white curds and yellowish whey.

Line a strainer with cheesecloth and pour in the curds. Place the strainer over a bowl or sink to catch the whey.

Let drain for 15–30 minutes, then mix in salt. For creamier ricotta, drain less time; for firmer texture, drain longer.

Store in an airtight container in the fridge for up to a week. Use within a few days for the best flavor and texture.