What IS shaving gel?

[elite]

Seriously! Why does shaving gel come out of the can as a gel but when rubbed, it foams!? What is it that causes this?

[Doctor Jackson]

Because it's formulated to do just that. Think of "soft soap" as compared to bar or powdered soap.

This site gives a full chemical breakdown and explanation of the ingredients in Gillette's brand of shaing gel:

http://neon.chemistry.ox.ac.uk/course/ityeartwo/html2/GILLETTESHAVINGGEL.htm

My guess, based on the explanations, is that the Glycereth-26 and the PEG-150 distearate are what gives the product its gel properties while the Lauramide DEA causes the gel to foam when rubbed on the face (or wherever).