The food lab better home cooking through science ( PDFDrive ) 108

whichresemblecoiledballsofyarn,slowlystarttouncoil.
•At140°F:Oneoftheseuncoiledproteins,ovotransferrin,
beginstobondwithitself,creatingasemisolidmatrixthat
turnstheeggwhitemilkyandjelly-like.
•At155°F:Theovotransferrinhasformedanopaquesolid,
thoughitisstillquitesoftandmoist.
•At180°F:Themainproteinintheeggwhite,ovalbumin,
will cross-link and solidify, giving you a totally firm but
stilltenderwhite.
• Beyond 180°F: The hotter you get the egg, the more
tightly the egg proteins bond, and the firmer, drier, and
more rubbery the egg white becomes. Eventually,
hydrogen sulfide, or that “rotten-egg” aroma, begins to
develop.Congratulations:youreggisovercooked.

ALTITUDEANDBOILING

B

ecause of gravity, the higher you go, the fewer

air molecules there are in a given space—so the air
is less dense. Lower density means lower
atmospheric pressure, and lower atmospheric
pressure means that water molecules in a pot need
less energy to escape into the air. In Bogotá,
Colombia, where my wife is from, for example,
you’re a good 8,000 feet above sea level and water
boilsatatemperatureabout14to15degreeslower
thanitdoesatsealevel.

The graph below charts the boiling temperatures
ofwaterasyougointohigheraltitudes.Thealtitude
effectcanwreakhavoconrecipes.Beansdon’tcook
right. Pasta never softens. Stews take longer to
braise. Pancakes can overrise and deflate. Go high
enough, and you won’t even be able to cook
vegetables,whichneedtobeheatedtoatleast183°F
tobreakdown.

For some of these problems, most notably
involving stews, dried beans, and root vegetables, a
pressure cooker can be a lifesaver. It works by
creating a vaportight seal around the food. As the
water inside it heats up and converts to steam, the
pressure inside the pot increases, because steam
takes up more space than water. This increased
pressurekeepsthewaterfromboiling,allowingyou
to bring it to a much higher temperature than you