and make it less runny, and thus allow the
bubbles to survive long enough to accumulate
into a sizeable mass. What gives the mass of
foam a useful kitchen lifetime is the white’s
team of proteins.
How the Egg Proteins
Stabilize Foams
Stress Builds Protein Solidarity As is true
for the setting of heated eggs and custards, the
key to the stable egg foam is the tendency of
the proteins to unfold and bond to each other
when they’re subjected to physical stress. In a
foam this creates a kind of reinforcement for
the bubble walls, the culinary equivalent of
quick-setting cement. Whipping exerts two
kinds of physical stress on the proteins. First,
as we force the whisk through the white, the
whisk wires drag some of the liquid with
them, and create a pulling force that unfolds
the compacted protein molecules. And second,