Homemade Parmesan

Warm the milk in a large, heavy-bottomed pot over medium heat to about 90°F (32°C).

Stir in the mesophilic starter culture and calcium chloride if using; let sit for 5 minutes.

Add diluted rennet to the milk, stirring gently for about a minute.

Cover and let the milk coagulate for 45 minutes to 1 hour until a firm curd forms.

Cut the curd into 1/4-inch cubes with a long knife, then let rest for 5 minutes.

Slowly heat the curds and whey to 125°F (52°C), stirring gently to prevent curds from matting.

Maintain this temperature for 30 minutes, stirring occasionally.

Turn off heat and let the curds settle for 10 minutes.

Using a slotted spoon, transfer curds into a cheese mold or cloth-lined basket, pressing gently to remove whey.

Let the cheese drain at room temperature for several hours, then salt the surface generously.

Age the cheese in a cool, humid environment for at least 6 months, turning regularly, until it develops a hard, granular texture and sharp flavor.

Grate or shave the homemade Parmesan as desired.