The Science of Cooking

Textbooks have been written about the science of cooking. After all, in many ways a kitchen is a laboratory. The cook induces controlled reactions to selected solids and liquids through the introduction of heat, cold, acids, and alkalines. These reactions change the nature of these solids (otherwise known as food) and make them edible. Put that way, it can seem like pretty dry stuff. You might not be actively thinking “science” when you're steaming broccoli, but regardless, you're changing cellular structure.

A bit of basic knowledge, however, helps understand why things happen the way they do, and knowledge is power. Here are just a few “reactions” that affect 20-minute cuisine. More will surface as we proceed:

• Adding salt to your water for cooking pasta raises the boiling temperature. Why is that useful? Higher temperature means that your pasta will cook more quickly. A bit of salt in the water adds flavor as well, although this method might not be appropriate if you're watching your sodium intake.
• Baking soda is a chemical compound (sodium bicarbonate) that helps make muffins and pancakes rise through a reaction—with acid in other ingredients—to release carbon dioxide bubbles and cause a quick rise. What you're cooking is actually being “inflated.”
• Yeasts are actually alive and release carbon dioxide as a by-product of just plain living. They take a little longer to do their stuff for foods such as breads. To start to grow, they need all the things that you provide when you fire up the bread machine: food (flour), moisture, and heat. Sourdough makes perhaps the most dramatic use of yeast. It is the sour (yeast) that not only raises the bread, but lends that wonderful chewy texture and rich flavor.
• You've probably noticed that fresh greens, like lettuce, wilt if left out too long. It's probably intuitive, but nevertheless interesting science to explore why. A leaf is made up of a multitude of tiny cells, each holding, among other things, water. When all the cells are full, a leaf is firm and crispy. When the cells lose some of their water, they wilt. If the wilting hasn't gone on too long, it can be reversed by soaking the leaves in water for a while, then drying them off in a salad spinner. Voilà—crispy lettuce.