WORLDCOFFEEEVENTS
ESPRESSOMACHINETESTINGAND
EVALUATION
2017
Contents
Introduction...............................................................................................................................................2
1.EspressoMachineRequirements........................................................................................................2
1.1Configuration.................................................................................................................................2
1.2WaterSupplyInformation.............................................................................................................2
1.3ElectricalSupplyInformation........................................................................................................2
1.4Portafilters.....................................................................................................................................2
1.5FilterBaskets.................................................................................................................................3
2.ManufacturerRequirementsandResponsibilities.............................................................................3
2.1GroupSizeandFilterBaskets........................................................................................................3
2.2SubmissionofFilterBasketsforDimensionalTesting...................................................................3
2.3Installation.....................................................................................................................................3
2.4Operation/Maintenance/Repair....................................................................................................4
2.5MachineRemoval..........................................................................................................................4
TestingandEvaluation............................................................................................................................4
Overview.............................................................................................................................................4
3.1PreparationforTesting.................................................................................................................4
3.2AdjustmentduringTesting............................................................................................................4
3.3AccesstoInternalComponents.....................................................................................................4
3.4QuantitativeTemperatureTesting................................................................................................4
3.5QuantitativePressureTesting.......................................................................................................5
3.6FilterBasketConsistencyTesting..................................................................................................5
3.7QualitativeTesting........................................................................................................................6
3.8DisqualificationduringQualitativeTesting...................................................................................6
3.9RankingofResults.........................................................................................................................6
3.10ConfidentialityofResults............................................................................................................6
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EspressoMachineTestingEvaluation
2017
Introduction
Thepurposeofespressomachinetestingistoascertainthatcandidateespressomachinesmeet
minimumperformancecriteria,andtoassessthesuitabilityofthesemachinesforuseascompetition
espressomachineswithinthesystemofworld,national,andregionalcompetitions,includingWorld
BaristaChampionship(WBC),WorldLatteArtChampionship,andWorldCoffeeinGoodSpirits
Championship.Thisdocumentprovidesinformationrelatedtothetypeofmachinebeingsolicitedfor
WCEuse,installationinthetestingenvironment,requiredmanufacturersupportduringthetests,and
informationabouttheteststhemselves.Testingisperformedbyanad-hoccommitteeconvenedby
theWCEBoardofDirectors.AllreferencestoWBCrulesrefertothe2017WBCRulesandRegulations,
version.
1.EspressoMachineRequirements
1.1Configuration
Espresso machines are to be 3-group, semi-automatic espresso machines, equipped with two nonautomatedsteamwands,oneneareachendoftheespressomachine,andahotwaterspigot.Bysemiautomatic, we mean that brewing is initiated and terminated manually, by human actuation of a
mechanicalorelectro-mechanicaldevice,suchasapush-button.Electronicvolumetricortimedcontrol
ofespressobrewingisnotallowed.Bynon-automatedsteamwand,wemeanthatsteamingisinitiated
andterminatedmanually,byhumanactuationofamechanicalorelectro-mechanicaldevice,suchasan
actuationlever,knob,orfootpedal.
1.2WaterSupplyInformation
Duringtesting,theespressomachinewilldrawbrewing/steamingwaterfromabottledwatersupply,
and discharge waste water to a drain bucket. The chemical makeup of the water shall conform to
SCAA/SCAEstandardsforwaterquality.
1.3ElectricalSupplyInformation
Theelectricalsupplyatthetestsiteis230V50Hz.
1.4Portafilters
Fiveportafiltersshallbesupplied,ofwhichthreeshallbesuppliedwithdouble-spoutsandtwoshallbe
modifiedsuchthattheflooroftheportafilterismachinedaway(bottomlessconfiguration).Theinside
diameterofthebored-outfloorshouldbethesameasthatoftheportafilterbody.Thesetwoportafilters
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willbeusedforquantitativetemperatureandpressuretesting.Portafiltersasprovidedonthesubmitted
machinesshallhaveasinternaldepthsufficienttohouseafilterwith20gnominalcapacity.
1.5FilterBaskets
Candidatemachinemanufacturersshallequiptheirmachineswithfilterbasketswithanominalcapacity
of 20g ± 1g of coffee ground for espresso, the value typically used in WCE competitions. Adequate
headroomabovethedoseshouldbeprovidedsuchthatwhentheportafilterwithbasketand20gdose
ismountedtothegroupassembly,thetopofthetampedcoffeebedisnotdisturbed.
2.ManufacturerRequirementsandResponsibilities
2.1GroupSizeandFilterBaskets
The nominal diameter of the portafilters (e.g., 58mm, 57mm, 54mm, etc.) shall be disclosed and
deliveredtotheWCEtestingcommitteebyMarch1st,2017tomakesurethatsuitabletestingfixtures
are available for use during the WCE testing event. Candidate machine manufacturers submitting
espressomachinesusingfilterbasketswithdiametersotherthan58mmshallsupply4filterbasketsfor
theconstructionoftestingfixtures,withbasketdepthof27mmifpossible,toGregoryScace,Espresso
Research,LLC,22304RollingHillLane,Laytonsville,MD20882,USA.
Pleasenotethatthisfacilitydoesnothaveareceptionist,andmanufacturersarerecommendedtosend
packagesthatdonotrequireasignature.DeadlineforreceiptisApril1st,2017.
2.2SubmissionofFilterBasketsforDimensionalTesting
Eachmanufacturershallsubmitanadditional30filterbasketsforaseriesofdimensionalconsistency
measurementsthatwillbeperformedpriortotheWCEtestingevent.Thefilterbasketsshallbeidentical
tothetypethatwillbeusedbythecandidateespressomachine,andwillhaveanominalcapacityof20
+/-1-gramscoffeegroundforespresso,thevaluetypicallyusedinWCEcompetitions.Eachfilterbasket
shallbemarkedwiththeapplicantCompanyname(orabbreviatedinitials)andsamplenumber:0130.ThebasketsshallbeshippedtoVincentFedele,FedExCopy&PrintCenter,A-160,750StonyPoint
Rd.SantaRosa,CA95407.ThedeadlineforreceiptisMarch15th,2017.
Pleasenotethatneitherfacilitymentionedabovein2.1and2.2,hasareceptionist,andmanufacturers
arerecommendedtosendpackagesthatdonotrequireasignature.
2.3Installation
The manufacturer is responsible for installing the machine prior to the tests, and insuring that the
machineperformstothemanufacturer’ssatisfaction.Themanufacturer(oritsagent)shallsupplyand
installallnecessaryequipmenttoconnecttheespressomachinetothewatersourceanddrain,including
pumps required to meet the espresso machine’s inlet pressure requirement, accumulator tanks, all
tubingandfittings.
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2.4Operation/Maintenance/Repair
Itisthemanufacturer’sresponsibilitytoensurethattheespressomachine’soperationalparametersare
withintheWBCrulesandspecificationsofthesetests,andthatthemachineoperatesasexpectedby
themanufacturer.Themanufacturerisresponsibleformaintenanceandrepairofitsespressomachine
duringthetests.Thisincludestheequipmentrequiredtomeet2.1.
2.5MachineRemoval
Manufacturers shall be responsible for draining, decommissioning, packing, and transporting their
machinery after testing is concluded, and shall supply all required equipment and personnel for this
purpose.
TestingandEvaluation
Overview
ThequantitativetestingphaseisdesignedtoensurethatcandidatemachinesareadjustabletoWBCspecifiedbrewingtemperatureandpressurespecifications,andthattheymeetreasonablestandardsfor
repeatability.Althoughcandidatemachinesmustmeetorexceedthequantitativetestthresholdvalues
inordertobeconsideredforWCEsponsorship,qualitativetestingwillstillbeperformedinorderforall
testparticipantstolearnasmuchaspossiblefromthisuniqueopportunity.
3.1PreparationforTesting
Priortoquantitativeandqualitativetesting,themanufacturershallensurethatitscandidateespresso
machine is adjusted such that temperature and pressure fall within the values specified in the WBC
OfficialRulesandRegulations.
3.2AdjustmentduringTesting
Adjustmentstotemperatureandpressureduringamachine’squantitativetemperatureandpressure
testingareonlyallowedperthetestingrequirements,orwiththepermissionofthetestingcommittee
chairandconsensusofthetestingcommittee.Adjustmentsarepermittedduringthequalitativephase
oftesting,providedthattheadjustedtemperature/pressurearewithinthespecificationsoutlineinthe
currentWBCrules.
3.3AccesstoInternalComponents
The manufacturer’s designated service personnel shall provide access to internal components of the
respectivecandidateespressomachinesasrequestedbymembersofthetestingcommittee
3.4QuantitativeTemperatureTesting
Tests shall be performed per the 2017 WCE Procedure for the Measurement of Brewing Water
Temperature in Espresso Machines. Tests will be performed on multiple groups operating
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simultaneously,includinggroups1and2,1and3,2and3.Responsetostepchangesintemperaturewill
bemeasured.Anarbitrarypairofgroupsmayberetestedwithsimultaneoussteamactuation.
3.5QuantitativePressureTesting
Pressuremeasurementshallbeperformedatthegroups,undertheflowconditionsspecifiedinthe2017
WCE Procedure for the Measurement of Brewing Water Temperature in Espresso Machines.
Measurementswillbeobtainedoneachindividuallyoperatinggroup,andonpairsofsimultaneously
operatinggroups(groups1and2,1and3,2and3).Themaximumallowabledifferencebetweenthe
highestandlowestofthe9pressurevaluesis0.4bar(6poundspersquareinch).
3.6FilterBasketConsistencyTesting
Asampleof30filterbaskets,submittedpersection2.2,willbemeasuredfordimensionalconsistency
using a digital filter imaging system developed for this purpose. We will examine the consistency in
dimensionaluniformityofthebasketsprovided.Dataofallmeasurementswillbesharedanonymously
witheachapplicant.Filterssubmittedwillbesortedwithrespecttototalopenareaanddimensional
uniformity of hole size distribution. Of the 30 submitted baskets, 28 must meet the following
specifications:
a) RangeofTotalOpenArea-Thetotalopenareaofall28samplesmustfallwithin90%to110%
oftheaveragetotalopenareaofthe28baskets,e.g.,AVGTotalOpenArea+/-10%(e.g.Ifthe
AVGTotalOpenAreais40sqmm,thenallbasketsshouldfallwithina20%rangeof36.0-44.0
sqmm(i.e.,40+/-4sqmm)).
b) Rangeofholesizes-95%ofholesshallhaveeffectivediametersthatfallwithinarangeof100µm
(Note: Because some methods do not produce circular holes the imaging system assigns an
effectivediameterbasedonthemeasuredholearea).Requirement(b)isintendedtoprovidea
limitonthenon-uniformityofholesizeswithinafilter.
c) Otherrequirements-Nomorethan1%ofholescanbeblocked.
d) ExtractionTesting-Tworandomlyselectedbasketswillbeforwardedtothemachinetestsite
forextractiontesting.Atthetestsite,aseriesofextractionswillbepulledatbrewingratios(the
ratiooftheweightofgroundcoffeetoweightofbrewedespresso)between50and80%.These
valuesbracketthebrewingratiostypicallyseeninWCEcompetitions.Atthetestingsite,wewill
determine the percent concentration and extraction yield by plotting measurements
obtained with a coffee refractometer on a brewing control chart. The filters and machine
combination must be capable of extractions that fall within 9-15% concentration and 18-22%
extractionyield.
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3.7QualitativeTesting
Espresso machines will be qualitatively evaluated by teams assembled from members of the WCE
QualifiedTestingCommittee.Thegeneraltopicscoveredunderthisevaluationarecontainedinthe2017
WCEQualitativeEspressoMachineEvaluationTestForm.Testersshallqualitativelyscoretheespresso
machinesineachcategory,basedontheirpersonaljudgement,andthejudgementofthetestteam(s).
Scoringlevelsandweightareoutlinedinthetestform.
3.8DisqualificationduringQualitativeTesting
Thetestingcommitteemaydisqualifyacandidatemachinethatexhibitssignificanttechnicalissuesthat
would,intheopinionofthetestingcommittee,makethemachineunsuitableforWCEcompetitions.
Suchissuesmightincludethefailureofcontrolstoperformreliably,oranuncoveredusabilityissuenot
detectedinquantitativetesting,suchasagrosschangeinpressurerampingwhenoperatingmultiple
groupscomparedtoonegroup.
3.9RankingofResults
Allespressomachinespassingthequantitativerequirementsandnotdisqualifiedunder3.8areeligible
for WCE sponsorship consideration. The score applied during qualitative testing will be used to rank
eligiblemachinesfordesirabilityasthenextWCEcompetitionmachine.Thisrankingistheopinionof
thetestingcommitteeastofitnessforcompetitionuseanddoesnotselectthenextWCEcompetition
machines.
3.10ConfidentialityofResults
Resultsmaybediscussedamongmembersofthetestingcommittee,butcommitteemembersmaynot
discussresultspubliclyatanytime.Manufacturersareentitledtoacopyoftheirrespectiveresultsonly.
Manufacturersarefreetodiscusstheirindividualresultsastheyseefit.
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