The grilled cheese is one of the chameleons of the food world. It can be lunch for a picky temperamental 5-year-old. It can be drunk food for an awake-at-3-a.m. college student. It can even be upscale hipster food truck fare. One more thing it can be? A chemistry lesson. The people from the Reactions YouTube channel, who in the past have used chemistry to explain the quality of New York bagels and the proper way to cut avocados, did a deep dive into the world of grilled cheese.
While we all know that the ideal sandwich is made of the meltiest cheese we can find, the video above goes to great lengths to explain what gives various cheeses their different melty characteristics. The secret, it turns out, is in the pH. Sharper, more crumbly cheeses (a.k.a. the ones that screw up your sandwich) have very low pHs. An ideal range is between 5.3 and 5.5. Cheese like gouda and manchego fall right into that sweet spot. American cheese, often held up as the melty ideal, comes in at 5.8 on the pH scale.
If more high school chemistry classes used lessons like this, we could get a lot more kids hooked on science. Maybe literally.