Italian: Simple Fresh Mozzarella (Acid-Only Coagulation Method)

Recipe by Kayla Lammy <klamm3@illinois.edu>

(makes about four fist-sized balls)

Mozzarella is a fresh cheese common in southern Italy. It is made by a process called “pasta filata” which translates to “spun paste.” In this process, formed curd gets heated in hot water or hot whey and is stretched and formed into desired texture and shape. In the southeast region, Puglia, cow’s milk is commonly used. In the southwest region, buffalo milk is more popular (“buffalo mozzarella”).

There are two main proteins in milk: casein and whey. First, milk is acidified, either by using citric acid, a bacteria culture that produces lactic acid, or white vinegar like we are doing here. Acid lowers the pH of the milk and allows the casein proteins to start sticking together, or coagulating, leaving behind the liquid whey. Rennet is traditionally added as well. Rennet, originally sourced from the digestive systems of ruminant animals, contains enzymes that further help the milk coagulate. Rennet coagulation will form a more stretchy and smooth mozzarella, whereas acid-only will be a bit more crumbly. We wanted to make an acid-only version so that it was more ingredient-friendly for the home cook.  

Ingredients:

• 1 gallon whole, non-homogenized milk (like Kilgus Farms)
• 7 fluid ounces white vinegar
• 1-2 Tablespoons table salt (to add to whey)

Serving Pairings  

• Olive oil
• Flaky sea salt
• Fresh ground black pepper
• Sliced tomatoes  
• Balsamic vinegar/balsamic vinegar reduction  
• Fresh basil

Procedure:

1. To a stock pot, add 1 gallon of whole, non-homogenized milk.
2. Heat on low on the stovetop, stirring constantly. Carefully watch the temperature, checking it frequently. Once the milk reaches 115*F, remove from the heat. Be careful not to overheat.
3. Once off the heat, stir in the vinegar until well incorporated. You should see the milk start to form curds. Cover with lid and let rest for 10-15 minutes.
4. Remove lid. Using a slotted spoon, scoop the curds that have formed into a bowl or fine mesh strainer. Leave liquid whey in the pot.
5. Using your hands, take a handful of the curd and gather it into a ball. Squeeze the ball in your hands until most of the liquid whey has escaped. Set ball aside and repeat for remaining curd.
6. Heat remaining whey on low heat until it reaches about 149*F. You can add 1-2 Tbsp of salt here if desired. Remove from heat.
7. Working with 1-2 balls at a time, place back into warm whey for about 30 seconds. The warm whey will help make the curd more pliable to work with.
8. After 30 seconds, remove the ball and use your hands to start stretching the ball, folding it back, stretching and folding it back. After a couple stretch and folds, place back into the warm whey and repeat this process 3-6 times, or until mozzarella becomes more smooth and stretchy. Once desired texture is reached, form back into a ball. Once the ball is reformed, drop it back into the warm whey, pull it back out, and do a final sealing/smoothing of the ball.

1. At first, curd may not stretch well. Be patient and keep repeating step 8.
2. Be cautious of working with the warm curd. You may need to let it cool for a few seconds before touching, but if it’s too cool it will be hard to stretch and fold it.

9. Place final balls into a water bath using cool tap water and a few ice cubes for 15 minutes.
10. Slice and enjoy!