I have some kind of obsession with cheese, both from a scientific and gastronomic point of view. I’m fascinated with the fact that when making cheese, you start with a liquid, heat it up, add some stuff to help the part of it firm up, and then either eat it as-is, or fiddle with it more to make it even tastier. You can eat it fresh, you can ferment it, dry it, smoke it, and process it in so many ways it’s hard to count; and of course, many people’s favorite: you can eat it melted. I really do love cheese.

In my cheese-loving journey, I’m most fascinated with one cheese in particular: mozzarella. When eaten fresh, it’s a very mild, and for some people, an acquired taste – some may find it a bit bland. When put on a pizza or in a sandwich (which is then toasted), it turns into this wonderful melted piece of heaven. It melts perfectly and leaves perfect little cheesy puddles of flavor and happiness.

I’ve probably wasted around a hundred liters of milk while trying to make something that resembles mozzarella. In theory, it’s a simple process: you get some cheese curds from milk, collect and drain them, and then melt them in a very hot leftover whey, or even water. In practice, this last step often ends up in a disaster, for many reasons, most of which are human (my) error.

The various types of mozzarella production (with or without starter, with or without rennet, etc.) are beyond the scope of this post. In this post, I want to describe a very simple and quick (less than 20 minutes from fresh milk to fresh mozzarella) method to get some very tasty mozzarella, which particularly shines when melted as it has a bit lower moisture content than traditional mozzarella that is intended to be eaten fresh.

This method uses only three ingredients: fresh milk (pasteurized milk, which is easier to get in most countries should also work, although I couldn’t quite get the wanted result until I switched over to fresh, untreated/unprocessed milk; UHT milk will not work here), white distilled vinegar, and salt.

The only piece of equipment one may not have in their kitchen is a thermometer, and it’s basically mandatory here (there are approximation methods, which I’ll quickly go over below).

The measurements of ingredients are: 1.5 L milk, 90 mL vinegar, 8 g salt (around 1.5 teaspoons).

The method:

  1. pour milk in a pot, and heat it to a temperature between 45 and 49 °C, stirring constantly to disperse the temperature evenly (if you don’t have a thermometer, dip your finger in the milk, and when you can only manage to hold it in for a count of 3-4 seconds, the milk is at the target temperature). turn off the heat.
  2. add vinegar and gently stir milk from the outside in (moving milk from the sides of the pot to the center) – it will quickly start to curdle
  3. cover the pot and let the curds rest for 3 minutes
  4. collect the curds together by gently pressing them to the side of the pot, until you get a half-melted homogenous mass
  5. transfer the cheese to a bowl or, better yet, a colander placed over a bowl, and start working it with your hands, to get most of the whey out of it, for approx. 2 minutes (the motion here is kind of like kneading the cheese with both your hands)
  6. while working the cheese, add salt to the leftover whey, and then heat the whey back up to a temperature of approx. 80 °C (again, if you don’t have a thermometer, the liquid should be steaming, but not boiling)
  7. put your cheese ball in the hot whey for 5-8 seconds, then remove it from the liquid, and squeeze it hard with both your hands (a bit of stretching/kneading here is okay, but don’t overdo it). repeat this process (cheese goes into whey for 5-8 seconds, then squeeze it really hard to get the whey out) two or three more times
  8. put the cheese in a bowl of ice-cold water for 3 minutes

After this last step, the cheese can be eaten as-is, or wrapped in a plastic wrap and then put into an airtight container in the refrigerator; the other method of preservation is making a brine from approx. 230 mL cold water and 5 g (1 teaspoon) salt, and placing the mozzarella ball in it. The cheese can probably be kept in the refrigerator for up to a week, although it never lasts that long in my house.

The yield I consistently get is around 160 g of cheese.

My attempt at showcasing the melting capabilities of this cheese:

Some notes and thoughts

Even though we know that “maximum gel firmness”, ie. casein concentration occurs at the pH < 4.6 (which is the isoelectric point of casein) (Phadungath, 2005), I suspect that the pH value of this method is much lower than 4.6. This poses a problem because the whey is basically unsuitable for consumption, because of its sourness, and needs to be discarded. I also tried to make some ricotta from this whey, but was unsuccessful.

The step number 5 in the list above could be modified by adding a small amount of salt to the cheese while it’s being kneaded. This will improve the taste of the cheese, but slightly complicates the method.

The step number 6 could be modified, so that plain water is salted and then heated up to the same temperature, instead of whey. When made this way, the taste of the cheese is milder and appropriate if one plans to eat it fresh, because, as already mentioned, some acidity lingers from the very acidic-tasting whey that’s left over.

Reference used

Phadungath, C., 2005. The mechanism and properties of acid-coagulated milk gels. Songklanakarin J. Sci. Technol, 27(2), pp.433-448.