Published on Nov 3, 2015 
 
 This week Reactions is taking a look at some cheesy chemistry in the form of a sandwich. We're giving you some science based tips on how to make the perfect grilled cheese sandwich. Consider this a chemical ode to one of the finest comfort foods ever created, the grilled cheese sandwich. Cheese making is an incredibly complex chemical process, and at a certain point, you may have learned the hard way that some cheeses simply don't make the grill grade. Why is it that some cheeses melt perfectly while others crumble into a nasty, oily mess? Today we're going answer that question for you, and while we're at it, we wanted to offer you some scientific advice on how to optimize your ingredients for the perfect grilled cheese experience. 
 
 
 
 Go check out "The Kitchen As Laboratory," a fantastic book about science and cooking, which inspired this episode: http://www.amazon.com/The-Kitchen-Lab... 
 
 
 
 
 
 Find us on all these places: 
 
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 Music: 
 
 Pure Natural - Touch me 
 
 Sam Leopard - Soul 
 
 
 
 Writer/Producer: 
 
 Kirk Zamieroski 
 
 
 
 Executive Producer: 
 
 Adam Dylewski 
 
 
 
 Scientific consultants: 
 
 Jennifer Kimmel, Ph.D. 
 
 Darcy Gentleman, Ph.D. 
 
 Sophia Cai 
 
 
 
 Sources: 
 
 The Kitchen as Laboratory - http://www.amazon.com/The-Kitchen-Lab... 
 
 
 
 On Milk Proteins - http://www.milkfacts.info/Milk%20Comp... 
 
 
 
 Texture of Cheese - http://www.journalofdairyscience.org/... 
 
 
 
 On Processed, "American" Cheese - https://pubs.acs.org/cen/whatstuff/st... 
 
 
 
 FDA on standards on American Cheese - https://www.fsa.usda.gov/Internet/FSA... ||||| There are some things we don’t need scientists to tell us — like the fact that cheese is delicious and was created by the dairy gods to please us — but there are other questions we need answered by the professionals in order to live our best lives. Like what the ideal kind of cheese is for a perfectly gooey, melty grilled cheese. Here comes the science! 
 
 A three-minute video from the series Reactions, hosted by the American Chemical Society, delves into the science of how cheese melts: it all comes down to how casein proteins clump together into spheres called micelles, which are held together by calcium and are full of fat. The surface of a micelle is negatively charged, so usually the little balls would bounce away from each other. 
 
 But when lactic acid gets involved, the micelles smack into each other and create chains that trap water and turn into a mess of cheesy goo. Cheeses that age longer contain more lactic acid, lowering its PH. That means sharper cheeses have a lower pH than their counterparts, which don’t age as long. 
 
 According to the American Chemical Society’s video, what this all means is that the ideal pH level for a cheese used to make grilled cheese is perfectly balanced between 5.3 to 5.5 (here’s a list [PDF] of PH levels in food). Any lower and cheese will release all its oil when heated, leaving curdled, clumpy clusters. 
 
 So what should you choose? Try gouda, gruyére or manchego. If you’re choosing between mild and sharp cheddar, go with mild — it has the texture you want, and won’t break down like its sharp counterpart. 
 
 If you want suggestions on how to cook that grilled cheese once you’ve selected which variety you want, check out our somewhat scientific We Tried It investigation. 
 
 For more science and cheese and cheese science, check out the video below:
– Looking for the perfect cheese for the ultimately gooey, perfectly melted grilled cheese sandwich? Good news: Scientists with the American Chemical Society have put out a three-minute video from the society's "Reactions" series on YouTube all about that very subject. And the winners are ... gouda, gruyére, or manchego, with mild cheeses melting more beautifully than sharp. It's all about how casein proteins clump together (the resulting spheres are called micelles) when cheese melts. These micelles, which are held together by calcium and are gloriously fatty, are negatively charged, meaning those tiny balls bounce apart. Add lactic acid, however, which goes up the longer a cheese ages, and those micelles smack together, trapping water and getting all gooey, reports Consumerist. But wait, there's more. The older the cheese, the more lactic acid, which in turn lowers the cheese's pH—thus sharper cheeses have a lower pH and mild ones a higher pH. The ideal pH, in fact, is right between 5.3 and 5.5, with cheese of lower pH releasing their oils when heated and getting clumpy. This is why gouda, gruyére, or manchego are ideal but on the milder side; if they age too long and become sharper, the pH dips too low and the cheese breaks down more easily, meaning you could end up with a curdled mess while heating it. (Check out why this cheese tests best for pizza.)