The Science Of Melting Cheese

Ever notice that some cheeses melt better than others? Some become an oily mess when exposed to heat, some barely change shape at all, while others melt into gooey goodness. Of course, there’s science behind this. Here are some factors to keep in mind when making your next dish of mac n’ cheese, pot of fondue, grilled cheese, or any other cheese based recipe. 

As a cheese is exposed to heat, the molecular bonds that hold casein proteins together in a mesh begin to release. This mesh is what gives a cheese its structure so as it gives way, the cheese begins to collapse. Interspersed throughout the casein protein mesh are fat and water. The amount of each of those impact the cheeses ability to melt. Soft, high-moisture cheeses like mozzarella have a lower melting point than aged, low-moisture cheeses like a cheddar or gruyere. Hard, dry cheeses usually meant for grating, like Parmigiano-Reggiano, have the highest melting point and don’t melt well unless moisture is added as another ingredient. Higher fat cheeses tend to melt better than their low/non-fat counterparts. 

Another factor that impacts a cheese’s meltability is the level of acidity. As cheese is a fermented food it is not feasible to make without acidification, whether from acid producing bacteria or direct acid addition. Along with the proteins, fat, and water in the mesh mentioned above, there is also calcium which acts as “glue.” Acid dissolves calcium, allowing the structure of the cheese to loosen. But too much acid and the casein proteins attract very strongly to each other. So if a cheese has too little acid or too much acid (paneer), it won’t make a good melter. They could get softened, but not melted. The acid level has to be just right to make a cheese get stretchy, oozy. 

All of that is to say, ask your cheesemonger for tips when planning what cheese to use in a recipe!

Check out this recipe for a very creamy mac and cheese on our recipe blog!