On food and cooking the science and lore of the kitchen ( PDFDrive ) 1160

thicken(center).Ascookingcontinuesandthe
temperatureapproachestheboil,thegranules
swell even more and leak starch chains into
the liquid (right).It’s at this stage that the
saucereachesitsmaximumthickness.
Cooling,FurtherThickening,and
CongealingOncethestarchinasaucehas
gelated,itsamylosehasleakedout,andthe
cookjudgesthesaucetobeproperlycooked,
hestopsthecooking,andthetemperatureof
thesaucebeginstofall.Asthemixturecools
down,thewaterandstarchmoleculesmove
withlessandlessenergy,andatacertain
pointtheforceofthetemporarybondsamong
thembeginstoholdthemoleculestogether
longerthantheyarekeptapartbyrandom
collisions.Gradually,thelongeramylose
moleculesformstablebondsamong
themselves,thekindofbondsthatheldthem
togetherinthegranuleinitially.Water
moleculessettleinthepocketsbetweenstarch
chains.Asaresult,theliquidmixturegets


progressivelythicker.Iftheamylose
moleculesareconcentratedenough,andthe
temperaturefallsfarenough,theliquid
mixturecongealsintoasolidgel,justasa
gelatinsolutionsettlesintoajelly.(Bushy
amylopectinmoleculestakemuchlongerto
bondtoeachother,solow-amylosestarches

areslowtocongeal.)Thisisthewayinwhich
piefillings,puddings,andsimilarsolidbut
moiststarchconcoctionsaremade.
Judge Sauce Consistency at Serving
Temperatures It’s important for the cook to
anticipate this cooling and thickening. We
create and evaluate most sauces on the stove
at high temperatures, around 200ºF/93ºC, but
whenthey’repouredinathinlayerontofood
and served, they immediately begin to cool
and thicken. However thick a sauce is in the
pan, it’s going to be thicker when the diner
actuallytastesit,anditmayevencongealon
the plate. So sauces should be thinner at the