2024剑桥雅思讲义Multiple_Choice_Questions_Strategy_Practice.docx

HomecheesemakingHomecheesemakinghasbeeninpracticeforthousandsofyearsandcomprisednearlyallcheeseproductionuntilthe19thcentury.Whilefactorycheeseproductionhastakenoverthemajorityofthemarket,manypeoplestillmakecheeseinthetraditionalfashion.Milkcontainsawidevarietyoffatsandproteins.Someofthesearesuspendedsolidsandminerals;othersareliquids.Theprocessofseparatingthesolidsfromtheliquidsiscurdling;thewhitesolidremainderisknownascurds,andthegreenishliquidremainderwhey.Cheeseiscurdsinawidevarietyofforms.Softcheesesarelittlechangedfromtheoriginalcurd;theyaretypicallydrainedbutnotpressed,andareusuallyunaged.Semisoft(orsemihard)cheesesaredrainedandlightlypressed,andmaybeaged.Hardcheesesaredrainedandwellpressed,andarealmostalwaysaged.Tdcausemilktocurdlerequiresacurdlingagent.Thereareawidevarietyofcurdlingagentsavailableinnature,bothplantandanimalbased-aquicksearchoftheinternetW川showsometoyou.Inpractice,onlyafewareregularlyusedincheesemaking.Vinegarandlemonjuicearecommonlyusedinsoftcheeses,suchasricotta;theycreateastickycurdinsmallflecks.Tartaricacidisthesharp,lemonycurdlingagentthatmakesmascarponecheese,andcreatesaveryfinestickycurd.Formostsemisoftandhardcheeses,rennetisused.Therearethreetypesofrennetincommonusage.Themosttraditionalrennetisananimalrennet;thisisanenzymetakenfromthedigestivetractofmammals.Forvegetarians,manycompaniesareproducinga"vegetable*rennet.Thesearenottrulyvegetable,butaremicrobialbased.Therearetwotypesofvegetablerennet.Themoretraditionalrennetisbasedonnongeneticallyengineeredbacteria.Unfortunately,itscurdisoftenill-suitedformanyhardcheeses.Typicallyusedinmoderntimesisonemadefromgeneticallyengineeredbacteriathatmaketheanimal-rennetstyleenzymes.Inadditiontobeingvegetarian,ithasahigherdegreeofreliabilityandconsistencythananimalrennet,andiswidelyrecommendedforuseinhomecheesemaking.Agedcheeseschangeflavorduetothemicroorganismsthatmetabolizethesugarsandproduceby-products(typicallybacteriarelatedtolacticacidcreation)whosetastepeopleenjoy.Notethathavingthewrongkindofmicroorganisms,whileunlikelytoeverbedangerous,willleaveyourcheesetastinglikevinegaroralcohol,whichgenerallytastesquitebad.Bothbacteriaandmoldsareusedincheesesforaging.Bacteriaareusedinalmosteveryagedcheese.Therearetwomaintypes:thermophilic(whicharefoundinyogurt)andmesophilic(whicharefoundinbuttermilk).Therearevariousspeciesthatbelongtoeachcategory,butasanamateur,thehomecheesemakerdoesn'tneedtoworryaboutthat.Asformolds,thereareawidevarietythatareused,andeachhasitsownuniquepropertiesandflavors.SomeofthemorewidelyusedonesarePenicilliumroqueforti(bluecheeses)andPropionicShermani(Swisscheeses).Molds,unlikethebacteriausedincheeses,canspreadfromcheesetocheese,andthusshouldbeisolatedasmuchaspossiblewhenaging.Thelongeracheeseisaged,thestrongerittastes;thisiswhyParmesancheeseandPecorinoRomanocheesehavesuchstrongflavors.Additionally,cheeseswithmolds,suchasbluecheeses,oftendeveloptheirflavorfasterthanthosewithoutmolds.Colorisrelatedtotwothings:thenaturalcolor(whichisusuallyacreamywhitetopaleyellow),andadditives.Themostcommoncoloradditiveisannatto,anextractofthedarkredseedsofplantsintheBixacaefamily,typicallygrowninSouthAmerica.Theirdarkred/orangecolordilutesintothetypicalcheddar-yellowthatwe'reallfamiliarwith.Annattocoloringisgenerallyavailableintwoforms:powderandliquid.Thepowdercantaketimetodissolve,andshouldbeaddedasearlyinthecheesemakingprocessaspossible(preferablyduringpasteurization,astheheathelpsitdissolve).Theliquidextractiseasilymixedin,andcanbeaddedatanypointbeforethecurdlingagentisadded.Traditionalfoodcoloringdoesnotworkwellatallforcoloringcurds;ittendstoremaininthewheyinsteadofthecurd.However,addingfoodcoloringtouncoloredcurdsaftertheyhavebeendrainedbutbeforetheyhavebeenpressedleadstoanattractivemottledpatternrarelyfoundincommercialcheeses.Generalhomecheesemakingrules Alwayspasteurizeyourmilk-evenifyouboughtitfromthestore.Leaveyourutensilsinitwhileyoudothis.Thiswillsterilizeyourpotandutensils,andguaranteethattheonlythingsinthemilkaregoingtobewhatyouputthere. Whenpasteurizingmilk,donotforgettostir.Ifyou'reforgetful,setatimer.Ifyouforgettostir,themilkwillscald;scaldedmilkshouldneverbeused. Doyourbesttoavoidcontaminatingyoursample.Trynottoputanythingthat'snotclean(includinguncleanhands)intoyourcheese. Makemilk-cheesesinbatchesofatleasttwogallonstosavetime(thisrequiresalargepot).Source:https:en.WikibOokS.orqWiki/Cookbook:HomeCheeSemakinqQQuestions1-10ChoosetheappropriatelettersA,B,CorD1. MostcheesemakingA. wasdoneathomeuntilthemiddleofthelastcentury.B. isnowadaysdoneindustrially.C. wasdoneintraditionalfactoriesinthe19thcentury.D. iscurrentlyperformedbytraditionalmeans.2. CurdsA. areonesubstancethatremainswhenthesolidandliquidfatsandproteinsinmilkareseparated.B. comeinvariousformsbutareoftengreenishincolour.C. areacomponentofcheeseaswellaswhey.D. areusedtomakemilkfromfatsandproteins.3. PressingA. isperformedmostinthecaseofhardcheeses.B. israrelyperformedinthecaseofsemihardcheeses.C. isg