Sterilize all of the equipment that you will need to make mozzarella including a large pot, draining spoon, thermometer, butter muslin, large knife, 2 large bowls, and a colander.

Add calcium chloride to chilled milk in a late port and stir in the diluted citric acid.

Heat the milk on the stove until it reaches 89 degrees F, while constantly stirring to prevent scalding the bottom.

Once temperature is at 89 degrees F, remove the pot from the heat and stir in the diluted rennet. Cover pot and leave to set for 25 to 30 minutes.

Check the curd. It should be firm with a clean break. A clean break can be tested by inserting a sterilized knife into the milk and lifting up at an angle. The curds should break cleanly around the knife while the whey rushed into the gap you have formed. At this stage the texture and look of the curds should be somewhere between jelly and thick yogurt. If it isn't ready, allow to sit for an additional 5 minutes and test again. Repeat until you have the right consistency.

When it is ready, cut the curd with a knife into 1 inch cubes while still in the pot. Place the pot back on the stove and heat to 108 degrees F. Stir the curds gently while heating. If your curds are still soft and delicate at 108 degrees F, continue to heat until they are firmer and have a slightly springy feel.

Scoop out the curds into a butter muslin lined colander. Leave to drain for 5 minutes. While the curds are draining, prepare one bowl of cool salty ice water and another with 150 degree F water (non-salted).

Take a handful of mozzarella curd and place under the hot water for 20 seconds using your draining spoon. Remove from the water and carefully stretch the curd until it is smooth and flexible (this takes a minute to get so your first ball of mozzarella might end up being a test ball). If the curd does not stretch easily, place back in the bowl of hot water for further heather before stretching and molding into a ball.

Once mozzarella has been molded into a nice round ball, plunge it into the ice cold salt-water bowl. Continue with the rest of the mozzarella curd.

Mozzarella will be ready to eat after it has spent 10 minutes in the ice cold salt water.