Science and Cooking: From Haute Cuisine to Soft Matter Science - Week 3

As I posted in my October 13th blog entry, I've enrolled in an on-line course about the relationship between science and cooking. A very video heavy week this time out - food porn fans would really appreciate all the detail that went into the making of this course. 

Here's what went down on the third week.

• The guest presenters this time out are Joan Roca, who runs the world-famous restaurant El Celler de Can Roca in Girona, Spain with his two brothers; and Dan Souza, senior editor for Cook's Illustrated Magazine, and current cast member of the America's Test Kitchen television show, radio program and podcast.
• This week we learned about the various phase transitions foods can go through in the cooking process. While a change in temperature can cause a phase transition, a change in pressure can also make this happen.
• A pressure cooker works by trapping some steam as water inside it boils, thus increasing the pressure and raising the boiling point. When the boiling water reaches this higher boiling point, it transfers heat to the food more quickly than water at just 100 degrees Celsius. This is a much better way to explain how a pressure cooker works than the method used to describe what happened in Boston back in April of this year.
• Want to cook the perfect egg, one with a temperature of about 64 degrees Celsius, perfectly every time? As water boils at a lower temperature as you gain altitude, just climb a tall enough mountain. Unfortunately, the boiling point of water on the top of Mount Everest is about 71 degrees Celsius, so you're going to need a bigger mountain.
• Chef Roca then demonstrates some of his renowned sous-vide cooking techniques by cooking, among other things, eggs and a fillet of sole.
  
  
  
  
• Another method to cause a phase transition is to use a rotovap, which is used in laboratories for the removal of solvents from samples by evaporation, and in cooking for the preparation of distillates and extracts. Check eBay for one if you ever need to distill the essence of something in one of your dishes.
  
• The concept of entropy has been introduced; I don't recall ever hearing about entropy in either elementary or high school science class, but I'm learning about it as part of a course about cooking, go figure.
• To be fair, I don't recall getting as much background in the half semesters of elementary school home-ec class either. Maybe it's time it should...
• Still haven't clapped for the equation of the week. This time it's U = CkBT.
• A chemical breakdown of fats and a discussion about the science of supercooling follows, along with an explanation of why you can't make water as salty as you can sweet. Thanks to this course, I now know that the solubility of any compound, is similar to the phase transition between a solid and a gas. 
• I scream, you scream, this week's lab involves the making of ice cream - sweet.