Place the pot back on the stove over medium heat and warm the curds to 105°F. Stir slowly as the curds warm, but try not to break them up too much. Remove the pan from the heat and continue stirring gently for another 5 minutes. The curds will eventually clump together and separate more completely from the yellow whey.
Knowing how to make your own mozzarella is a dangerous thing. Knowing that at any moment, should the desire present itself, you could whip up your very own ball of creamy mozzarella, still warm from the whey whence it came? Yes. Very very dangerous. Here's how to do it.
Compounding the dangerousness of homemade mozzarella is the fact that it comes together in about twenty minutes. You warm the milk with some citric acid (not as scary as it sounds), add the rennet to separate the milk into curds and whey, heat it again, knead stretch knead, and then you have mozzarella. It's basically magic.
Don't be scared off by the citric acid and the rennet. Both things sound like something Batman might encounter on a bad day in Gotham, but they are actually normal, everyday ingredients.
Citric acid is just a powdered form of the same mouth-puckering acid found in lemons and limes. It's added here to help acidify and coagulate the milk. Rennet can be found in both tablet or liquid form, as well as in vegetarian or...er...non-vegetarian versions. Its job is to set the proteins in the milk and form solid, stretchy curds.
Both citric acid and rennet can usually be found at a good grocery store or food co-op. If you're having trouble tracking something down, however, take a look at the links below for places to buy the ingredients online.
When it comes to milk, almost anything goes: whole, 2%, skim, cow, goat, raw, organic, or pasteurized. The only rule is to avoid milk that has been ultra high temperature (UHT) pasteurized. This particular method of pasteurization denatures the proteins in the milk to the point that they lose their ability to fully solidify into curds. Be careful when buying organic milk as many brands are UHT pasteurized and the packaging doesn't always indicate this. If your mozzarella ends up looking like soupy cottage cheese, try switching to another brand of milk.
Adapted from New England Cheesemaking Supply Company
What You Need
1 1/4 cup water
1 1/2 teaspoon citric acid
1/4 rennet tablet or 1/4 teaspoon liquid rennet (Not Junket rennet, see note below)
1 gallon milk, whole or 2%, not ultra-pasteurized*
1 teaspoon kosher salt
5 quart or larger non-reactive pot
Measuring cups and spoons
8" knife, off-set spatula, or similar slim instrument for cutting the curds
1. Prepare the Citric Acid and Rennet: Measure out 1 cup of water. Stir in the citric acid until dissolved. Measure out 1/4 cup of water in a separate bowl. Stir in the rennet until dissolved.
2. Warm the Milk: Pour the milk into the pot. Stir in the citric acid solution. Set the pot over medium-high heat and warm to 90°F, stirring gently.
3. Add the Rennet: Remove the pot from heat and gently stir in the rennet solution. Count to 30. Stop stirring, cover the pot, and let it sit undisturbed for 5 minutes.
4. Cut the Curds: After five minutes, the milk should have set, and it should look and feel like soft silken tofu. If it is still liquidy, re-cover the pot and let it sit for another five minutes. Once the milk has set, cut it into uniform curds: make several parallel cuts vertically through the curds and then several parallel cuts horizontally, creating a grid-like pattern. Make sure your knife reaches all the way to the bottom of the pan.
5. Cook the Curds: Place the pot back on the stove over medium heat and warm the curds to 105°F. Stir slowly as the curds warm, but try not to break them up too much. The curds will eventually clump together and separate more completely from the yellow whey.
6. Remove the Curds from Heat and Stir: Remove the pan from the heat and continue stirring gently for another 5 minutes.
7. Separate the Curds from the Whey: Ladle the curds into a microwave-safe bowl with the slotted spoon.
8. Microwave the Curds:(No microwave? See the Notes section below for directions on making mozzarella without a microwave.) Microwave the curds for one minute. Drain off the whey. Put on your rubber gloves and fold the curds over on themselves a few times. At this point, the curds will still be very loose and cottage-cheese-like.
9. Microwave the Curds to 135°F: Microwave the curds for another 30 seconds and check their internal temperature. If the temperature has reached 135°F, continue with stretching the curds. If not, continue microwaving in 30-second bursts until they reach temperature. The curds need to reach this temperature in order to stretch properly.
10. Stretch and Shape the Mozzarella: Sprinkle the salt over the cheese and squish it with your fingers to incorporate. Using both hands, stretch and fold the curds repeatedly. It will start to tighten, become firm, and take on a glossy sheen. When this happens, you are ready to shape the mozzarella. Make one large ball, two smaller balls, or several bite-sized bocconcini. Try not to over-work the mozzarella.
11. Using and Storing Your Mozzarella: The mozzarella can be used immediately or kept refrigerated for a week. To refrigerate, place the mozzarella in a small container. Mix a teaspoon of salt with a cup of cool whey and pour this over the mozzarella. Cover and refrigerate.
• Making Mozzarella Without the Microwave: Instead of microwaving the curds to make mozzarella, warm a large pot of water to just below boiling (about 190°F). Pour the curds into a strainer and nestle the strainer into the pot so the curds are submerged in the hot water. Let the curds sit for about five minutes. Wearing rubber gloves, fold the curds under the water and check their internal temperature. If it has not reached 135°F, let the curds sit for another few minutes until it does. Once the curds have reached 135°, lift them from the water and stretch as directed.
• Milk for Mozzarella: Almost any milk can be used for making mozzarella: whole, 2%, skim, cow, goat, raw, organic, or pasteurized. Pasteurized milk is fine to use, but make sure that it is not ultra high temperature (UHT) pasteurized. The proteins in UHT milk have lost their ability to set into curds.
• Melting Homemade Mozzarella: I've found that homemade mozzarella doesn't always melt as completely as store-bought mozzarella, especially if I've overworked the cheese and it has become very stiff. If you're planning to make pizza or something else where melting is desired, use a whole-fat milk and make extra-sure not to overwork the cheese. It can also help to grate the cheese rather than slice it.
• Using Junket Rennet: Junket rennet is less concentrated than other kinds of rennet and isn't ideal for making cheese. If this is all you have access to, try using 1-2 whole tablets to achieve a curd.
• Using Leftover Whey: Making mozzarella leaves you with almost 3 1/2 quarts of whey! You can use this whey in place of water in bread recipes and other baked goods, mix it into smoothies, or add it to soups.