Welcome to the world of artisanal milk fermentation, where the art of turning milk into gold (or at least, slightly-tarter-but-still-delicious cheese) meets the science of lactose conversion!
Start by gathering the following:
Heat the milk to 86°F (30°C), then stir in the mesophilus culture. Let it sit for 45 minutes. Repeat as necessary until you've achieved the perfect curd.
Stir in the rennet and let it sit for another 10-15 minutes. You'll know it's done when it reaches the perfect consistency (ask a dairy scientist for specifics, we're not exactly sure what we're talking about).
Cut the curd into 1-inch cubes and press the mixture into a mold. Let it chill for 4-6 hours, then voilà! You've got yourself some artisanal cheese, complete with a side of existential dread about the future of dairy farming.