"Multi-tasking," the managerial buzzword these days, isn't a newconcept if you're talking about cooking. Eggs have been multi-taskingforever. And their importance in preparing a wide spectrum of foodsproves that eggs can perform any number of diverse and demanding roles.This is pretty impressive for something as compact as an egg.
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Egg whites are 88 percent water. Yolks nearly 50 percent. So thetask of contributing liquid to batters and doughs is an easy one foreggs. As flour absorbs liquid in baking, starch granules swell to formthe framework that becomes a cake, a muffin, a cookie. Eventuallymoisture converts to steam, a leaven so powerful that just one partliquid explodes into 1,600 parts steam. Break into a cream puff or apopover (high ratio of eggs) and their hollow centers provide dramatictestimony to steam's immense power. On a smaller scale, the steamcreated from the liquid in just one or two eggs works quietly in mostbatters and doughs to boost rising.
The proteins in eggs also enable them to act as leavens but in a completely different manner. Proteins unwind and stretch to form the flexible, elastic film that encases air bubbles. When eggs are beaten, they can expand to a foam that's up to eight times their original volume. Beaten egg whites hold millions of tiny air bubbles, which lift angel-food and sponge cakes, meringues, and souffles. Even in batters containing baking powder, beaten eggs whites are an additional source of leavening.
Each month, we've featured a different kitchen science article by the Inquisitive Cooks, Anne Gardiner and Sue Wilson , with tips, facts, and unique ideas to give you a whole new perspective on cooking.
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What happens if you leave a bottle of milk in the fridge too long, or if youryogurt sits out in the sun? You get rancid yuck, right? But somehow, if done justthe right way, a similar process can result in fragrant, pungent, yummy cheese.How can this possibly happen? View the Webcast and watch as we investigate the creamy, rich--and sometimes stinky world of cheese.
While the elastic quality of proteins is lost when eggs are cooked,the firming of proteins allows eggs to perform yet another function. Astheir proteins coagulate, eggs bind ingredients together. Meat loavesare less likely to crumble. Casseroles serve in tidier portions. And acrumb coating holds more tightly to a veal cutlet when its been dippedin egg before being rolled in breadcrumbs.
In creme caramel and quiche, egg proteins unwind, then bondto form a mesh that traps milk or cream in a soft gel. And in a stirredcustard or creme anglaise, eggs thicken just as effectively, but atlower temperatures than flour or cornstarch.
Lecithin and the other emulsifiers in egg yolks come in handy too.Tiny droplets of fat stay suspended throughout emulsions such asmayonnaise, hollandaise, and bearnaise when coated with a thin film ofyolk. Without the emulsifying properties of eggs, these special sauceswouldn't be as luxurious, nor as smooth.
It's eggs, not lemon, that add the rich yellow color to a lemon piefilling. And of course they contribute flavor to any food in whichthey're used.
Looking at just some of the ways we use eggs makes us think perhapswe give too little credit to their special qualities. They might notlook as splashy as a frilly head of lettuce or announce their presencewith a searing burn of a hot pepper. But the humble little egg is surelyhandy in the kitchen and confirms that in cooking, this oneextraordinary character can indeed accomplish the work of many.
 | Anne Gardiner & Sue Wilson are the authors, with the Exploratorium, of the book The Inquisitive Cook. | ||
