Professor Wolke's FOOD 101, a light food science column, appears on alternate Wednesdays in the Food Section of The Washington Post and is nationally syndicated weekly by the United Feature Syndicate. In FOOD 101, Wolke answers readers' questions about anything and everything associated with food. No recipes, no health or nutrition advice. Just fun answers to things that people wonder about in the kitchen, at the dining table or in the supermarket. Click here to see a few samples.