On food and cooking the science and lore of the kitchen ( PDFDrive ) 1284
Bạn đang xem bản rút gọn của tài liệu. Xem và tải ngay bản đầy đủ của tài liệu tại đây (122.26 KB, 2 trang )
andConfectionery
Allsugarcandies,whetherbrittleorcreamy
orchewy,areessentiallymixturesoftwo
ingredients:sugarandwater.Cooksmanage
tocreateverydifferenttexturesfromthesame
materialsbyvaryingtherelativeproportions
ofsugarandwater,andthephysical
arrangementofthesugarmolecules.They
controltheproportionsastheycookthesugar
syrup,andtheycontrolthephysical
arrangementastheycoolit.Dependingon
howhotthesyrupgets,howquicklyitcools,
andhowmuchit’sstirred,itcansolidifyinto
coarsesugarcrystals,finesugarcrystals,ora
monolithiccrystal-freemass.Toalarge
extent,theartoftheconfectionerdependson
thescienceofcrystallization.
SettingtheSugar
Concentration:
CookingtheSyrup
Thefirstfactorthatinfluencescandytexture
istheconcentrationofsugarinthecooked
syrup.Confectionershavefoundfromlong
experiencethatcertainsyrupconcentrations
arebestformakingcertainkindsofcandy.
Generally,themorewaterthesyrupcontains,
thesofterthefinalproductwillbe.Sothe
cookmustknowhowtomakeandrecognize
particularsyrupconcentrations.Thisturnsout
tobeprettysimple.Whenwedissolvesugar
orsaltinwater,theboilingpointofthe
solutionbecomeshigherthantheboilingpoint
ofpurewater(seep.785).Thisincreaseinthe
boilingpointdependspredictablyonthe
amountofmaterialdissolved:themore
dissolvedmoleculesinthewater,thehigher
theboilingpoint.Sotheboilingpointofa
solutionisanindicatoroftheconcentrationof
thedissolvedmaterial.Thegraphinthebox
belowshows,forexample,thatasugarsyrup
thatboilsat250ºF/125ºCisabout90%sugar
byweight.
