On food and cooking the science and lore of the kitchen ( PDFDrive ) 42

manythatwouldmakethemilkunpalatableor
causedisease.Lactoseandthelactic-acid
bacteriathereforeturnmilksour,buthelp
preventitfromspoiling,orbecoming
undrinkable.
Lactoseisone-fifthassweetastablesugar,
andonlyone-tenthassolubleinwater(200vs.
2,000gm/l),solactosecrystalsreadilyform
insuchproductsascondensedmilkandice
creamandcangivethemasandytexture.
MilkFat

Milkfataccountsformuchofthebody,
nutritionalvalue,andeconomicvalueofmilk.
Themilk-fatglobulescarrythefat-soluble
vitamins(A,D,E,K),andabouthalfthe
caloriesofwholemilk.Thehigherthefat
contentofmilk,themorecreamorbuttercan
bemadefromit,andsothehigherthepriceit
willbring.Mostcowssecretemorefatin
winter,duemainlytoconcentratedwinter


feedandtheapproachingendoftheirlactation
period.Certainbreeds,notablyGuernseysand
JerseysfromtheChannelIslandsbetween
BritainandFrance,produceespeciallyrich
milkandlargefatglobules.Sheepandbuffalo
milkscontainuptotwicethebutterfatof
wholecow’smilk(p.13).
Thewaythefatispackagedintoglobules

accountsformuchofmilk’sbehaviorinthe
kitchen.Themembranethatsurroundseach
fatglobuleismadeupofphospholipids(fatty
acidemulsifiers,p.802)andproteins,and
playstwomajorroles.Itseparatesthe
dropletsoffatfromeachotherandprevents
themfrompoolingtogetherintoonelarge
mass;anditprotectsthefatmoleculesfrom
fat-digestingenzymesinthemilkthatwould
otherwiseattackthemandbreakthemdown
intorancid-smellingandbitterfattyacids.
CreamingWhenmilkfreshfromtheudderis
allowed to stand and cool for some hours,