Why Does hot Cheese Burn Tongue?

Why does the cheese on a hot piece of pizza burn your tongue while the crust doesn't?
- Mike OConnor (age 70)
Champaign, IL. USA

Cheese is dense- mostly water and fat. It has a high heat capacity per volume (~3J/cm³K), and conducts heat fairly well. So lots of heat flows quickly from the cheese to your tongue.

The crust is largely air and has little water. It has much lower heat capacity per volume (mostly flour, so ~0.26g/cm³*1.59J/gK= 0.4J/cm³K, really less because of the air). With all those air pockets, it doesn't conduct heat well either. So less heat flows toward your tongue, and more slowly.

Mike W., Tunc

We got the parameters from here:

http://www.engineeringtoolbox.com/specific-heat-capacity-food-d_295.html

Cauvain and Yang, "Bakery Food Manufacture and Quality: Water Control and Effects"

(published on 09/08/2015)