"Queso fresco is a white, slightly salty fresh cheese featured in Mexican and other Latin American cuisines. Its texture is somewhat firm and crumbly, similar to that of farmer's cheese. The cheese is ready to eat or can refrigerated for up to 2 weeks."
Pour milk into a heavy pot. Heat slowly to 90 degrees F (32 degrees C), stirring occasionally. Turn off heat and gently stir in the rennet solution.
Cover pot and let rest in a warm place, at about 90 degrees F (32 degrees C), until the curd forms a thick mass, about 40 minutes. Place your finger or spatula in the curd and gently lift to check for a clean break; it should split along a clean line and not be too soft or milky. Let rest for another 10 minutes if it isn't quite firm.
Cut curds into 1/4-inch cubes using your finger, a knife, or a spatula. Heat curds and the remaining liquid, or whey, to 110 to 115 degrees F (43 to 46 degrees C), about 15 minutes, stirring occasionally. Ladle curds into a colander; discard whey or keep for another use. Gently mix salt into the curds using your fingers.
Line a colander or plastic container with a cheesecloth; add curds and wrap cheesecloth around the top. Place a heavy weight on top, such as a small bowl filled with pie weights or a jar of water. Press for 4 to 6 hours.