Pour the milk into stainless steel, 1-gallon pan. Place on a medium burner.
Bring the temperature of the milk up to 180 F and remove from heat. If you are using sour milk, I suggest holding the temperature at 180 F for 10 minutes to kill bacteria.
Add vinegar to milk and gently stir until curds form.
Line a colander with cheesecloth and set in a large bowl. Pour the curdled milk into the colander, bundle the cheesecloth up and squeeze most of the whey out.
Enjoy the fresh cheese or take a bit more time to make queso seco.
To make queso seco, add a bit more salt (about 1/2 teaspoon total) and mix into curds. Gather cheesecloth and tie. Leave in the colander and place a weight on top to press more whey from the curds. Leave for about 10 to 12 hours. Remove from cheesecloth and refrigerate.
For cheese that lasts longer in the refrigerator... add 1/2 tsp of salt and place a weight on the bundled curds for 10 - 12 hours to make Queso Seco (Dry Cheese).