In a large, stainless steel pot, bring your milk to a temperature of 96 degrees F. Turn the heat off and sprinkle your packet of thermophilic culture on the surface of the milk. Allow it to hydrate for 30 seconds.
Gently stir the culture in with an up and down motion. Then cover the pot and let the culture work for 30 minutes.
Add the Rennet
After 30 minutes, measure out the rennet and add it to a 1/4 C. of cool water. Stir it into the milk on the stove, using a gentle up and down motion.
Cover the pot once again and allow it to sit for 40 minutes, undisturbed. After that time, the milk should have a firm set.
Cut the Curd
Use a long knife to cut the curd in a checkerboard pattern, about 1/2 inch - 3/4 inch rows. The whey that fills in as you cut should be clear (if not, then allow the milk to set an additional 5-10 minutes).
Allow the curds 5 minutes to rest, then bring the temperature of the pot back up to 96 degrees F. and stir the curds. They should start to become smaller over time.
Cook the Curds
Now it's time to heat up the curds. Over the next 30 minutes, heat the curds to 116 degrees F. Try to do this slowly, so keep the heat on the lowest setting. As the curds shrink, more whey will release.
After that 30 minutes, turn off the heat and allow the curds to remain at that temperature for an additional 30 minutes. The thermal mass of heat within the pot should hold the temperature steady during this time.
Drain the Curds
Once the curds are done, they will fall to the bottom of the pot. Line a colander with cheesecloth and transfer the curds to drain.
Tie the ends of the cheesecloth up at the corners, and hang on your cabinets for 30 minutes. During that time, the tightness of the cloth will press the curds together in a mass.
Press the Curds
You want to press your curds for at least 1 hour but no more than 3 hours. To do this, a flat plate topped with a gallon jug of water is sufficient.
As you press, the mass should come together nicely. While you can press for 3 hours, I always stick with an hour unless I lose track of time.
Break Apart the Curds
Once the hour passes, gently unwrap the cheesecloth from the mass and break the mass apart into curds. Salt the curds to your liking, then enjoy.
Cheese curds are best stored in a ziploc bag in the refrigerator.