Line a colander with a damp piece of muslin or cheesecloth and set in the sink or over a bowl.
Pour milk into a large pan. Heat to 93 degrees C. Stir well and add salt if using.
Add lemon juice a little at a time. Stir until curds separate. Ladle curds into the muslin. Fold muslin over curds and place a weight on top (this can be a bowl filled with water). Press lightly and let drain for 2 to 3 hours.
Your paneer is now ready to use in your favourite recipe!