Begin by heating 2 gallons of milk to 90°F. Leave remaining 2 gallons chilled.

Sprinkle both the Mesophilic and Thermophilic cultures onto the warmed milk. Allow to rehydrate for a minute, then stir in well. Leave the milk to culture for 30 minutes.

After the warm milk has cultured, add the citric acid solution to the chilled milk and stir thoroughly. You can do this either in a medium-sized pot, or just in the milk jars. Add the cold milk into the warm milk pot. Stir well to combine, and then heat the whole pot of milk back up to 90°F.

Pour the diluted rennet into the 4 gallons of milk. I like to do this over a slotted spoon or spatula to evenly disperse the rennet. Then gently stir it in with an up and down motion. Try not to break the surface of the milk. Stir for about a minute, then allow the milk to become still. It will begin to coagulate quickly.

Leave the curd to set for about 30 minutes. When you check it, it may look a bit stretchy, and different from a regular cheese curd. This is due to the citric acid, and is perfectly normal.

Cut the curd into 1” cubes, pausing for 5 minutes between each new set of cuts to allow the curds to “heal." See video for more details on cutting the curd.

Gently begin to stir the curds, bringing them up from the bottom of the pot. Don’t worry about cutting any overly-large curds down to size. Stir them gently and infrequently over the next 30 minutes, while heating the curds and whey to 110°F. You will need very little stirring; just enough to keep the curds from settling to the bottom and burning.

At the end of 30 minutes the curds should be starting to form a large mass, and look rather stretchy. Let them settle to the bottom of the pot, and remove from the heating element.

Pour off as much whey as you can from the pot, then set aside the curd mass to mellow. You can use a colander if it will fit in your pot. I prefer to pour off all the whey and keep the curds in the pot. Either way, drain off the whey, and return the curds to the pot either directly or in a colander. Let the curds rest in the pot, covered, for 30 minutes. Keep a thermometer in the curd mass to make sure they maintain about 110°F. You can fill a gallon ziplock bag full of warm water and place it on top of the curds to help maintain their temperature.

After 30 minutes, heat a medium sized pot with water up to 180°F. You will be stretching small amounts of the mozzarella at a time in this water. Maintain it between 170°-180°F. Prepare a cooling bath for the finished cheese by filling a large bowl halfway with ice water.

Pull the curd mass from the pot and set it on a large cutting board. Cut the curd into about 2” strips. Place one strip at a time into the pot of hot water. Using mozzarella gloves, check the curds every few seconds to see if they are ready to stretch. When they are ready they will be pliable and stretch without breaking. Gently pull the curds ever so slightly stretch the cheese. You really just need to double it over onto itself 3-4 times, patting and shaping it as you do so. It’s tempting to really pull and stretch the cheese, like I you would with cow milk mozzarella, but delicate goat milk mozzarella will have the best texture if you are very gentle with it! If the curds get too hot and begin to melt in the water, pull them out and leave them to cool on the cutting board for a couple minutes before stretching.

For balls of mozzarella, double over the strip of hot curds 3-4 times, then gently pat it into a ball. This is much like shaping bread rolls. For string cheese, double the curd strip over a few times before rolling it into a long snake-like rope, about the diameter of a stick of string cheese. You may need to dunk the curds into the hot water a few times as you stretch to keep the curds pliable. When you’ve gotten the shape you desire, place the cheese into the bowl of ice water to cool. See the video for more advice on stretching and shaping the curds.

Once you’ve stretched all the curds, place the mozzarella balls and string cheese into a saturated salt brine. Allow the cheese to brine until it reaches your desired saltiness. For me, that’s about 1.5 hours for string cheese and 3 hours for mozzarella balls. Be sure the check them and taste after about an hour in the brine to see whether they're salty enough for you. Gently pat the cheese dry and chill in the fridge. You can keep the mozzarella in a glass container or plastic bag in the fridge for about 10 days. Or else freeze the mozzarella for future use! The mozzarella balls shred or slice beautifully, and it melts like a dream. The string cheese should be nice and stringy for snacking too!