othertoformbrownpigmentsandahostof
newflavormolecules(p.778).Butifthe
juicesremainjuices,theyconstituteavery
basicsauce,aproductofthemeatthatcanbe
addedbacktomoistenandflavorthemassof
coagulatedmuscleproteinfromwhichthey’ve
beensqueezed.Theproblemisthatthemeat
orfishonlygivesupasmallamountofjuice
comparedtothesolidmass.Tosatisfyfully
ourappetiteforthosejuices,cookshave
inventedmethodsformakingmeatandfish
saucesfortheirownsake,andinanyquantity.
Themainthickeningagentinthesesaucesis
gelatin,anunusualproteinthatcooking
releasesfromthemeatandfish.Cooksalso
useotheranimalproteinstothickensauces,
buttheirbehaviorisverydifferentandmore
problematic,aswe’llsee(p.603).
TheUniquenessofGelatin

Gelatinisaprotein,butit’sunliketheother


proteinsthatthecookworkswith.Nearlyall
foodproteinsrespondtotheheatofcooking
byunfolding,bondingpermanentlytoeach
other,andcoagulatingintoafirm,solidmass.
Itturnsoutthatgelatinmoleculescan’teasily
formpermanentbondswitheachother,dueto
theirparticularchemicalmakeup.Soheat
simplycausesthemtoshakeloosefromthe

weak,temporarybondsthatholdthem
together,anddispersestheminwater.
Becausegelatinmoleculesareverylongand
gettangledupwitheachother,theygivethe
mixtureadefinitebody,andcanevensetit
intoasolidgel(p.605).However,gelatinis
relativelyinefficientatthickening.Its
moleculesareveryflexible,whilethoseof
starchandothercarbohydratesarerigidand
betteratinterferingwiththemovementof
waterandeachother.Thisisonereasonwhy
gelatin-thickenedsaucesareusually
augmentedwithstarch.Asaucethatcontains
onlygelatinrequiresalargeconcentration,