To make mozzarella cheese at home, follow these main steps:

1. Prepare citric acid and rennet mixtures by dissolving each in water separately.
2. Heat milk with the citric acid mixture until it reaches about 32°C (90°F).
3. Add the rennet mixture, stir briefly, then let the milk set undisturbed for about 5 minutes until it firms up like yogurt.
4. Cut the curd into cubes and gently heat to around 76°C (170°F) in hot water or whey.
5. Stretch and fold the curds repeatedly until smooth and shiny, then shape into balls.
6. Optionally, cool the mozzarella balls in ice water or whey to set.

This process uses simple ingredients like milk, citric acid, rennet, and salt to produce stretchy, fresh mozzarella cheese with a smooth texture.