Prepare the Milk:
Dissolve citric acid in 1/4 cup filtered water and add to cold milk in a large pot. Heat gently to 90°F (32°C), stirring occasionally.

Add Rennet:
Dissolve rennet in 1/4 cup filtered water. Pour into the warmed milk and stir slowly for 30 seconds. Cover and let sit undisturbed for 5–10 minutes, until curds form.

Cut and Cook the Curds:
Cut the curds into 1-inch cubes with a long knife. Heat the curds to 105°F (40°C), stirring gently to release whey.

Separate Curds and Whey:
Scoop the curds into a colander lined with cheesecloth. Allow to drain for 5 minutes, then squeeze gently to remove extra whey.

Stretch the Mozzarella:
Place curds into a bowl of hot water (170°F/77°C). Using gloves, stretch and fold the cheese until smooth and elastic. Set aside one-third of the curds for the filling.

Make the Stracciatella Filling:
Tear reserved curds into strips, mix with heavy cream and a pinch of salt to create the creamy center.

Assemble the Burrata:
Flatten the stretched mozzarella into discs. Spoon stracciatella into the center, fold the edges over, and pinch closed to seal.

Cool and Serve:
Dip the burrata balls into ice water to set their shape. Serve at room temperature, drizzled with olive oil and fresh basil if desired.