Silicone in the Kitchen

There are three basic kinds of rubber: natural rubber, which comes from latex, the sap of the tropical tree Hevea brasiliensis; synthetic rubber, which comes from a chemical plant; and silicone rubber, which comes from, well, a different chemical plant.

The last two were dreamed up by chemists to duplicate some of natural rubber’s unique properties and improve upon others. A synthetic rubber called neoprene was first marketed by DuPont in 1931, while a wide variety of silicone rubbers have been manufactured by General Electric and Dow Corning since the 1940s. These two man-made products inherited the silly name “rubber” from the natural material, which was so-christened by the English chemist and clergyman Joseph Priestley in 1770, when he found that it would rub out pencil marks…

Silicone bakeware has a remarkably useful set of properties. First, the material is inherently translucent, so a veritable kaleidoscope of bright colors can be incorporated into the products. (KitchenAid’s line of muffin pans, loaf pans and cake pans comes in red or blue.) They can withstand high temperatures without melting (i.e., without their molecules flowing apart from one another) because the molecules are very long and tightly intertwined, like a cold, leftover plate of Spaghetti with Glue Sauce. That’s also why you can take them directly from the oven to the freezer or vice versa without any fear of cracking; the molecules, while individually flexible, are so rigidly fixed in place that the material can’t expand or contract very much with changes in temperature.

Silicones don’t absorb microwaves, but like all microwave-safe utensils they can get hot in the microwave oven from contact with the heated food. Because silicones are chemically inert, the pans are dishwasher safe; caustic detergents can’t touch them. Also because of their nonreactivity, they are more or less nonstick; cakes and muffins release easily — most of the time — since you can flex the pans to pop them out. [Food 101]