Line a large metal colander with three layers of cheesecloth and place over the sink. Meanwhile pour milk and salt into large saucepan and heat over medium high heat. Check often with a digital-read thermometer until the milk reaches 185 degrees. Be sure to stir often so it does not burn on the bottom. Remove from heat and gradually stir in the lemon juice and vinegar until curdles form. Allow to rest for 10 minutes.