“A box without hinges, key, or lid, yet golden treasure inside is hid.” – One of Bilbo Baggins’ riddles for Gollum, The Hobbit. What can thicken a sauce, emulsify a custard, or leaven a cake? What can give a shiny glaze to a new loaf of bread, be whipped into sugary clouds of confection, or keep that mohawk sharp, beautiful, and pointing skyward? (Sorry, ’80s flashback there.) I am talking, of course, about the most excellent egg. Understanding the properties of the different parts of an egg, i.e. the whites and the yolks, can help make baking, especially pastry-making, a little less daunting.