ThickeningAgentsandMethods
Description
Students willgain anunderstanding of the gelatinizationprocess andwill beableto identifytwothickening agents and howtoprepare them. Theythenwillperformdifferent cookingmethodsusedto thicken aliquid.
LessonObjectives
Students willbeable to:
•identify a starch(flour)andhowitabsorbs a liquidinthegelatinization process
•prepare a roux(flourandfat)and a slurry(flourandwater)
•identify variousstages of a roux when itis cooked
•prepareawhitewash using cornstarch and coldwater,and
•thicken a preparedsauce or stockthroughreduction.
Assumptions
•Theteacher will becomefamiliarwiththe process ofgelatinizationand evaporation usingthe resources available.
•Theteacherwillexplainthatstarchneedsto be separatedinfat(roux) or suspendedinwater(slurryandwhitewash),andwilldemonstratethepreparationof a roux,slurry,andwhitewash.
•Theteacherwillbe able to demonstrate evaporation of a liquidresulting ina reduction.
SafetyConsiderations
General
•UseofproperPPE(personalprotectiveequipment)atalltimes.
•Allfoodsafety proceduresmust always bereinforced. Forexample,keep hot foodshotandcold foods cold.
•Spills must becleanedup immediately. Students are tonotify theteacherof anybrokenglass or cookingtools.
Thisworkis licensedunder aCreativeCommonsAttribution-NonCommercial-ShareAlike4.0InternationalLicenseunlessotherwiseindicated.
Lesson-specific
•Students mustbe made aware that hotliquids can boil over, causing spillsandburns.Liquids can alsosplatterand/or create steam, resulting ina burn.
•Students may need tomodify how theycarrythepotwithtwoprotected hands on eithersideof the pot. Ifit’s tooheavy,studentsmayneedto modify their position orhave anotherpersondo theheavylifting.Useacartor trolleyif necessary.
•Heat-resistant tools shouldbe used.
Terminology
ausec:Ausec(Fr.)referstoaliquidthathasbeenheatedandreduceduntilitbecomesstickyandnearly dry.
boil:Toboilistocookfoodsquicklyinrapidlyboiling water (oranotherliquid) at 100°C (212°F).Starchneedstheliquidtoboiltobecomeabsorbedandnottastepasty.
gelatinization:Gelatinizationistheabsorptionofwaterinstarch,producingagel.
gluten:Glutenisacompositeofproteinsfoundincerealgrains,especiallywheat,thatgivesdoughitselasticity.
roux:Aroux(Fr.)isamixtureofequalpartsofflourandfatstirredtogetherandusedto thickensauces.
slurry:Aslurryisa thickeningagentthatincludesasmalleramountofflourintroduced intoalargeramountof waterandstirred,resultinginthestarchbeingsuspendedinthewater.
starch:Starchisawhite, odourless,andtastelesscarbohydratethatisthechiefformofstoredenergyincertainplantmaterial, especiallycerealsandpotatoes.
stir:Stirringisacookingtechniqueforseparatingstarchgranulessolumpsaresmoothedout.Usuallydonewithawhiskorspooninasaucepan.
whitewash:Awhitewashisathickeningagentmadefromasmalleramountofcornstarchmixedintoalargeramountof water andstirred,resultinginthestarchbeingsuspendedinthewater.
EstimatedTime
This theory and practicalcanbe includedinother ActivityPlans.Teachers can cover whendemonstrating in other modules.
70 minutestotal:
•30 minutesforroux-basedrecipe
•20minutesfor cornstarch or slurry-based recipe
•20minutesforreductionexplanation
RecommendedNumberofStudents
Upto24
Facilities
HomeEconomics teachinglab and/or Culinary Arts teaching kitchen
Tools
•cheesecloth(optional)
•container for storage
•saucepan
•scraper
•spoon
•strainer—conical or sieve
•whisk
Resources
Teachers can finddemonstrationsonline,buttheymustpreviewtowatchfor correct sanitationpractices, temperatures, andorganization.
RouxbeCookingSchool.Onlinelessons.
DemonstratingSkillsAndKnowledge
Procedure
Teacher-ledActivity
1.Introduce thickening agents and describetheprocess of gelatinization.
2.Demonstratethepreparationof a roux,mixingequalpartsoffatand all-purpose flour.
3.Demonstratecooking therouxand explain that the starchwill turna variety ofcolours.
4.Explain that cooking therouxforlongerresultsinthefinalproducthaving a differentflavourand colour.
5.Demonstratehowto preparea slurry.Emphasize theimportance of stirring thestarchbeforeitis added toaliquid.
6.Demonstratehowtoprepare a whitewash.Emphasize theimportanceofstirringthestarchbeforeitis added toaliquid.
7.Demonstrate the reduction of aliquid.
Student-ledActivity
1.Students will preparea roux and cook and taste it asthestarch turns brown.Milkwillbeadded tothreedifferent stagesof cooking therouxanditwill becooked until thick.
Students mayobserveand taste thethreedifferent sauces to comparetheir appearancesandflavours.
2.Students willprepare aslurry andcook it until thick to observethegelatinization process.
3.Reductionwill be demonstratedby cooking whippingcream on mediumheatfor15minutestonoticehow thick it becomes.
EvaluationGuidelines
Theresults of thestudent-ledactivity willmeetthefollowing requirements:
•desired consistency
•desiredtexture
•appropriatecolour showingthatthe starchhascooked inthe roux
The student will:
•work cleanlyandsafely
•be organized
•followprocedure withproperingredients
•be enthusiastic and take initiatives including tastingtheproducttounderstandit
•showself-direction inhelping others
•showgood judgment aboutwhen to gethelp, and
•showan interestinfairness forothers.
ExtensionActivities
Theroux-based saucemethod canbeincluded inthese types of recipe:
•cheesesauce for broccoli
•creamsoup
•cream sauce for pasta or meat
•brownsauce for roastmeat
•casserole