The salt keeps cheese from splitting
Cheese is a crowded mixture of fat, water and proteins. When ordinary cheese melts, its proteins can tighten and squeeze out fat, leaving a greasy layer instead of a smooth sauce. Emulsifying salts—often compounds such as sodium citrate—help loosen the proteins’ grip on one another. They can then help keep tiny fat droplets dispersed through the watery part of the sauce.
That matters in a cheesesteak shop, where the topping needs to flow over chopped meat rather than melt into a stretchy pile. Gentle heat makes the sauce thinner and easier to ladle, while its stabilized mixture stays creamy instead of separating into oil and curds.
The roll becomes part of the sauce
A generous pour changes the sandwich after it is assembled. Sauce settles into the spaces between meat and bread, and some of its moisture moves into the roll. The bread softens where it meets the cheese, while its crust and interior still give the filling something to sit on.
So the abundance is not just decoration: it makes the cheese a coating and a filling at once. The last bites can taste different from the first because the roll has had time to absorb some of that warm sauce.
