On food and cooking the science and lore of the kitchen ( PDFDrive ) 1057

browning. During the first stage, the batter
expands to its full volume. As the batter
temperature rises, the gases in the air cells
expand, chemical leavening releases carbon
dioxide, and beginning around 140ºF/60ºC,
watervaporbeginstoformandexpandtheair
cellsevenfurther.Duringthesecondstageof
cake baking, the risen batter is set into its
permanentshapebytheovenheat.Beginning
around 180ºF/80ºC, the egg proteins
coagulate, and starch granules absorb water,
swell, and gelate. The actual setting
temperature depends strongly on the
proportionofsugar,whichdelaysbothprotein
coagulation and starch swelling; in a highratio cake, the starch may not gelate until
close to 212ºF/100ºC. In the last stage, batter
solidification is completed, flavor-enhancing
browning reactions take place in the nowdried surface, and the cake often shrinks
slightly, an indication that it should be taken
outoftheoven.Anothertestofdonenessisto


probethecenterwithatoothpickorwirecake
tester, which should come out clean of any
batterorcrumbparticles.

Baking a cake. Left:A typical cake batter
includes starch granules from flour, egg
proteinsthatcoagulatewhenheated,andgas
bubbles incorporated during mixing, all
swimming in a syrup of water and sugar.

(Mostcakesincludesomeformoffat,whichis
not shown here for the sake of clarity.)
Center:When the mix is heated, the gas
bubblesexpand,causingthemixtorise.Atthe
same time, the proteins begin to unfold and
thestarchgranulesbegintoabsorbwaterand
swell. Right:At the end of baking, the fluid
batter has set into a porous solid, thanks to