Chances are you know exactly what cheese you like on your grilled cheese sandwich. Maybe you enjoy a little stringy mozzarella, creamy american, or tangy sharp cheddar. Well, according to science, you’re wrong! The American Chemical Society has broken down the science behind the iconic melty sandwich – and it turns out it’s all about pH!

I was surprised to find out that acid levels dictate the ultimate ‘gooeyness’ of cheese. Cheeses with an acidity in the range of pH 5.3 to 5.5 — such as gouda, gruyére or manchego — are best for being heated up in a sandwich.

Too much acidity (or a very low pH), aka ‘sharper’ cheeses, can break down while melting leaving you with a clumpy texture. So, if you are trying to pick the right cheddar cheese, go with the more mild option.

The latest video from the YouTube series Reactions, hosted by the ACS, explains the chemistry of the perfect grilled cheese sandwich in-depth. You’ve got to check it out below! 😜

As for me? I’ll stick with american cheese and a whole lot of butter. It made me smile when I was 5 years old and it still makes me smile today.