Pour milk into a saucepan set over medium heat. Heat milk until it registers 194 degrees F (90 degrees C) on an instant-read thermometer, about 5 minutes. Remove from heat.
Stir lemon juice and salt slowly into warmed milk. Let stand until milk curdles, 10 to 15 minutes.
Line a fine-mesh strainer with cheesecloth and place it over a large bowl. Pour milk mixture carefully into the lined strainer. Let stand until most of the liquid has drained off the ricotta, about 15 minutes. Discard drained liquid.