The Workbench: September 2012

Advertisement Q: I learned that when you combine sugar and eggs, you shouldn't leave them too long or the sugar will "cook" the eggs. Is this true? F.J., Seattle A: Usually when talking about cooking food, we are suggesting the use of heat to make radical changes in the chemical structure of the food. One of those changes is to denature proteins. In an egg yolk, proteins float around in a pool of water. The proteins are folded, which gives them room to float without bumping into other proteins. If they bump into other proteins, they combine, which ruins their relaxed nature. When you add sugar to egg yolks, the sugar combines with the water in the eggs. The more water that gets tied up with sugar, the smaller the swimming pool for the protein becomes. Because the protein is still folded, instead of making a nice regular mesh that normally happens with a cooked egg, you just get a hard clump of eggy protein. Don't wait around once you've poured the sugar into the yolk. Q: We use tofu for our vegan pumpkin pie. How should we handle the tofu? R.S., Orem, Utah A: Tofu needs to be "prepared" before used in baking by removing the excess water. To squeeze tofu dry, cut the block into slabs, and place the slabs on a baking sheet lined with clean paper towels. Cover the slabs with another baking sheet weighted with heavy cans, and let it sit for an hour. Q: Is potassium bitartrate the same as cream of tartar? S.R., Morgantown, W.V. A: Potassium bitartrate is the chemical name for cream of tartar, an acid transformed into a salt. However, the substance itself is not a cream, but a fine white powder that prevents sugar from crystallizing. Potassium bitartrate also is used as an ingredient in baked products and helps prevent the color of fresh fruits from running in batters. Dr. Klaus Tenbergen is certified as a Master Baker in Germany, South Africa and the United States. He is currently an assistant professor at California State University in Fresno, directing the Culinology® program, which blends culinary arts and the science of food. For more information about Culinology®, or to submit a question, contact Dr. Tenbergen at ktenbergen@csufresno.edu.