My obsession with coffee crept into my end of semester project, studying the science of frothing milk. This was done for my class on Heat Transfer, which covers the different ways heat is transmit between media.
To summarize, stainless steel does transmit heat to your hand faster than any other medium shown (better than a thermos, duh), due to it’s conductivity coefficient. That’s important when steaming milk, as you can quickly gauge milk temperature by holding the milk pitcher. The project was pretty ridiculous and involved lots of measuring temperatures with a meat thermometer. It’s probably the silliest experiment I’ve gotten away with during my Engineering degree, but it was great fun.
We made a lot of assumptions in order to perform the experiment, but the process of milk frothing, one maybe taken for granted by us coffee drinkers, is quite complex. What impresses me is the fully automated espresso machines. There could be more science behind making coffee than you would think.