Crafting the Perfect Grilled Cheese… With Science!!

Right on the cusp of spring but still chilly, gray and rainy, it’s no wonder that April has the unique honor of being designated National Grilled Cheese Month!

While we of course celebrate year round, we thought that the occasion presented a perfect excuse to address one of the most common questions a cheesemonger gets: what’s the best cheese for a grilled cheese sandwich?

As with anything else, asking someone obsessed with something a question about that very thing will provoke a response way, way longer and more involved than the asker bargained for (or even wanted). Never ones to disappoint, we’ve decided to take a deep dive into what exactly it is that makes a cheese worthy of being melted between bread!!

What it all comes down to in the end is the chemical makeup of the cheese and how different cheesemaking techniques result in very different behavior in the final product. We thought the most useful way to go about explaining this would be to point out the differences between how a few common melting cheeses (cheddar, Swiss-style and mozzarella) are made and how their production process affects how they melt. Get ready for some serious curd-nerding!!

While cheddar is often thought of as the go-to cheese for most melting applications, its reputation is, in truth, somewhat unearned. Since the term “cheddar” is not in any way protected in the USA, just about any product that vaguely conforms to customer’s expectations of a typical “cheddar” flavor, texture and appearance can label itself as cheddar cheese. In absence of any regulation, a typical supermarket will stock a dizzying array of products all sporting the name “cheddar”, even though sometimes not a even single one of them is made according to the traditional process.

Having been produced differently, these cheeses are chemically different and, as a result, will behave differently in the presence of heat.

One of the things that separates a true cheddar from the herd is, apart from its make process, the pH levels at various stages in its life cycle and the effect this has on the cheese’s physical makeup. Cheese is made up of milk protein, aka casein, molecules that have stuck themselves together (forming curds) and pushed out moisture (whey), trapping fat and minerals in the process. These casein molecules are made up of small protein particles held together by calcium phosphate, which acts as a sort of glue. This “glue” dissolves in the presence of acid, weakening the structure of the casein and, as a result, the structure of the cheese overall.

When traditional cheddar cheese is made, the milk is left to a reach a medium-low pH before the curds are formed, creating a higher-acid environment that eats away at the calcium glue holding the protein structures together. Additional acid is produced in the cheese during aging and storage, and by the time it’s ready to eat a well-aged cheddar will have lost much of its resilience. Since the structure of the cheese has been weakened, it will tend to collapse when heat is applied, separating from the fats and resulting in a gritty, oily texture. (Side note: this is true when talking about traditional, English-style aged cheddars. If you’re looking for melty cheddar goodness, a younger, higher-moisture cheddar will serve your needs perfectly!!)

By contrast, alpine-style cheeses such as Emmental or Gruyere (or domestic favorites like Alpha Tolman and Reading Raclette), which have a lower-acid environment during their make process, will melt more smoothly and evenly. The higher pH ensures that less calcium is dissolved, making for stronger protein bonds, which in turn protects the structure of the cheese and keep other solids like fats and minerals trapped snugly within the curds even when heat is applied. This leads to the coveted silky, ropey texture we’ve come to look for in dishes like raclette and fondue.  

Apart from the chemical processes at play, the physical handling of curds in alpine cheeses also contribute to their superior meltability. Whereas in cheddar making the curds are separated from their whey, pressed into blocks which are then stacked onto each other, then run through a mill to break them up, curds destined to become Comte or Appenzeller receive a more delicate treatment. The curds are left in the vat with their whey, where they are gently cooked and cut down into pieces no bigger than a grain of rice. Then, either by hand in the vat or via mechanical pump, the curds are pressed together and formed without ever having the whey drained off in a process referred to as “pressing under the whey”. This enables the curds to knit together without ever being exposed to air, eliminating cracks, fissures and pockets in the cheese. The result is an extremely smooth, “closed” texture and a low “friability” (aka ability to be crumbled) factor in the final cheese, which helps it hold together tightly during melting.

On the other end of the spectrum, there is of course what may very well be the world’s most famous melter: mozzarella. And though it’s notoriety comes most often from its role atop pizzas, to dismiss it as a grilled cheese ingredient would be a big mistake.

Mozzarella is part of a family of cheeses known as “stretched curd” or pasta filata. This style of cheese is named for the fact that the curd, immediately after forming, is cut and then kneaded by hand like dough. The cheesemaker repeatedly stretches the freshly formed cheese, folding it over onto itself before each pull. Much like layers in croissant dough or puff pastry, this process creates thin layers of protein, which are stacked on one another over and over again throughout the kneading, reinforcing one another. The result is the familiar bouncy, stretchy and snappy texture that makes melted mozzarella so universally beloved.

So, with all this in mind, our original question still stands: what type of cheese makes for the best grilled cheese?!

Given that each type brings something different to the table, our professional opinion as cheesemongers and disciples of hot cheese is that the best route to go is a blend. We recommend playing with proportions to meet your individual tastes and needs, but a typical winning combination should go something like this: a good cheddar for acidity and salt, an alpine style for sweetness and body, and a fresh or pasta filata cheese as a binding agent.

As always, the preference of the person doing the grilling is the most important factor in crafting the perfect grilled cheese. But, armed with a little science, we hope you’ll experiment often and freely!

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s