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This Is the Perfect Grilled Cheese, According to Science

“The Science of the Perfect Grilled Cheese Sandwich” explains that a perfectly melted grilled cheese is all about the gooeyness or stretchability of the cheese.

Science is an elusive, unforgiving mistress. Sure, it may have given us such monuments to human ingenuity as Dippin' Dots and The Magic School Bus, but that doesn't discount some really awful scientific creations. We're talking nuclear warfare, Dr. Zaius, and playable piano neckties.

Still, it's with wholehearted enthusiasm that we report to you that science has finally done something for the common man worth talking about. And you best believe it involves a whole lot of glistening, bubbling cheese.


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The American Chemical Society's YouTube series Reactions released a three-minute video last week detailing the gooey science behind the perfect grilled cheese sandwich. "The Science of the Perfect Grilled Cheese Sandwich" explains that a perfectly melted grilled cheese is all about the gooeyness or stretchability of the cheese. And that depends on one thing: how a cheese's casein proteins lump together into micelles. Or how they don't.

For those not in the know, micelles are spherical lipid molecules that are bound together by calcium and contain a large amount of fat. As it turns out, all micelles are negatively charged on their surface, and, as such, will not normally stick to one another.

Photo via Flickr user Daniel Lui

Photo via Flickr user Daniel Lui

That is, unless you bring glorious lactic acid into the situation. And you don't have to be Alton Brown to glean that lactic acid is found abundantly in queso. Lactic acid actually causes those micelles to bond to one another and trap water content.

But you don't want your cheese micelles all bound together, right? You want them stretchy and melty. Which all comes down to attaining the perfect pH balance in your cheese.

Ergo, melty cheese has proteins that can break away and melt—and that takes a pretty low pH, which lets calcium loosen things up. What the scientists found is that if the pH of your cheese is optimal, then the protein and fats can interact and make everything flow together into the perfect grilled cheese sandwich.


So what is the perfect pH for grilled cheese? 5.3 to 5.5, evidently. That means Cheddar, Gouda, and manchego are the best. And mild Cheddar is better than sharp.

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This explains why American cheese is the fave of, well, Americans. American cheese is made by melting two or more cheeses together and adding an emulsifier like sodium phosphate or potassium phosphate—and it has a pH of about 5.8, so it's pretty close to the sweet spot.

Why take a chance on using some random cheese that you have in the back of the fridge—you know, the one that hasn't grown fuzzy yet? Instead, when you are in search of the perfect cheese for the ultimate grilled cheese sandwich, remember to go for a pH of 5.5 to 5.8. Or just remember this: Cheddar, Gouda and manchego.

And that bright yellow, plastic-wrapped, processed American that never seems to go bad? It'll do pretty well too.