Egg White Foam
The physical stress of beating egg white can create a foam. There are two types of physical stress caused by beating them with a whisk, the first being that the whisk drags the liquid through itself, creating a force that unfolds the protein molecules. This process is called denaturation. The second stress comes from the mixing of air into the whites, which causes the proteins to come out of their natural state. These denatured proteins gather together where the air and water meet and create multiple bonds with the other unraveled proteins, and thus become a foam, holding the incorporated air in place. This is because the proteins consist of amino acids; some are hydrophilic (attracted to water) and some are hydrophobic (repelled by water). This process is called coagulation.
When beating egg whites, they are classified in three stages according to the peaks they form when the beater is lifted: soft, firm, and stiff peaks. Overbeaten eggs take on a dry appearance, and will eventually collapse. Egg whites will not beat up correctly if they are exposed to any form of fat, such as cooking oils or the fats contained in egg yolk.
Read more about this topic: Egg White
Famous quotes containing the words egg, white and/or foam:
“Today everything is different. I can’t even get decent food. Right after I got here I ordered some spaghetti with marinara sauce and I got egg noodles and catsup. I’m an average nobody, I get to live the rest of my life like a schnook.”
—Nicholas Pileggi, U.S. screenwriter, and Martin Scorsese. Henry Hill (Ray Liotta)
“It is worth the while to detect new faculties in man,—he is so much the more divine; and anything that fairly excites our admiration expands us. The Indian, who can find his way so wonderfully in the woods, possesses an intelligence which the white man does not,—and it increases my own capacity, as well as faith, to observe it. I rejoice to find that intelligence flows in other channels than I knew. It redeems for me portions of what seemed brutish before.”
—Henry David Thoreau (1817–1862)
“Yet ere I can say where—the chariot hath
Passed over them—nor other trace I find
But as of foam after the ocean’s wrath”
—Percy Bysshe Shelley (1792–1822)