Heat the Milk: Pour raw milk into a heavy-bottomed pot and place over medium-high heat. Warm slowly to 185°F (85°C), stirring occasionally to prevent scorching.
Curdle the Milk: Remove the pot from heat. Gradually add vinegar, stirring gently. Curds should form quickly. If whey still looks milky, add a little more vinegar, one tablespoon at a time.
Rest the Curds: Let the milk sit undisturbed for 10 minutes to allow the curds to fully separate.
Drain the Curds: Using a ladle or slotted spoon, transfer curds to a colander lined with cheesecloth or a tea towel, set over a bowl. Pour the warm whey over the curds to rinse gently. Let drain for 15 minutes.
Salt the Curds: Sprinkle salt over the drained curds and mix gently with a fork, tasting as you go, until seasoned to your liking.
For a crumbly queso fresco, gather curds in the cheesecloth and hang for 30 minutes.
For firmer, sliceable cheese: Twist cheesecloth to keep curds compact, return to colander, cover with a plate, and weigh down with 1–2 pounds (a jar, can, or mortar works).
Press & Chill: Press cheese for 1 hour. Remove from press and refrigerate until fully chilled.
Serve: Slice or cube the pressed queso fresco with a sharp knife. Wipe your knife between cuts for neat edges.