On food and cooking the science and lore of the kitchen ( PDFDrive ) 1290

Particles,Temperature,andStirring
InfluenceCrystallizationThecrystal“seed”
isaninitialsurfacetowhichsugarmolecules
canattachthemselvesandaccumulateina
solidmass.Theseedcanbeafewsugar
moleculesthathappentocometogether
duringrandommovementsinthesyrup.
Stirringandagitationhavetheeffectof
bumpingsolutionmoleculestogethermore
oftenthantheyotherwisewould,andthereby
encouragetheformationofcrystalseeds.
Otherthingscanalsoserveasseedsina
coolingsyrupandinitiatecrystallization.
Amongthemorecommonarethetinycrystals
thatformwhenthesyrupspattersontheside
ofthepanordriesoffonaspoon,andthat
thenarestirredbackintothesyrup.Dust
particlesandeventinyairbubblescanalsoact
ascrystalseeds.Ametalspooncaninduce
crystallizationbyconductingheatawayfrom
localareasofthesyrup,coolingthemandso
leavingthemsuper-supersaturated.


Experiencedcandymakersthereforeprevent
prematurecrystallizationbyusingwooden
spoons,avoidingagitationofthesyruponce
it’scookedandbeginstocool,andcarefully
removingdriedsyrupspatterfromthepan
wallswithamoistbrush.
Controlling Crystal Size and Candy

Texture The cook has to worry about
premature crystallization because candy
textureisaffectedbythesyruptemperatureat
which crystallization begins. Generally, hot
syrups produce coarse crystals, and cool
syrupsproducefinecrystals.Here’sthelogic.
Because more sugar molecules will arrive at
thecrystalsurfaceduringagiventimeinahot
syrup with fast-moving molecules than in a
cold, lethargic one, crystals grow more
rapidly in hot syrups. At the same time,
because stable crystalseeds areless likely to
form at higher temperatures — an aggregate
of a few sugar molecules is more easily