grain_sampling

G ra i ns a m p l i n g– a fa r m e r ’s guide

Spring 2003

2

Spring 2003

Dear member

In any supply ch a i n , business must be basedon understanding and meeting the needs ofb u ye rs . In the ‘ grain ch a i n ’ , fa rm e rs must fo rgelinks with merchants or end-users .

H oweve r, s u p p lying grain to a specification isnot easy. G rain is inhere n t ly va ri able ands p e c i fications become ever more stri n ge n t .Fa i l u re to meet specifications means fa rm e rsface price deductions or, in the wo rst case,re j e c t i o n . We have calculated that the annu a lcost to the industry is around £2.5 million.

M u ch of this cost could be saved if thequality data obtained by both the seller andb u yer of grain match each other we l l .A ch i eving this depends on adopting similars t a n d a rds for grain sampling and accura t ea n a lysis on and off the fa rm .

That is why HGCA seized the opportunity toge n e rate a greater understanding of samplingt h rough the ‘ G rain Sampling and A n a ly s i sP ro j e c t ’ . Funded 75% with a HM Tre a s u ry‘ I nvest to Save ’ grant and with 25% HGCAi n p u t , this guide is one of the pro j e c t ’s fi rs to u t p u t s .

The protocols included here do not re p l a c ei n t e rnational standards employed by sectorsof the tra d e .H oweve r, the HGCA p ro t o c o l s ,d evised by the industry, re p resent as i g n i ficant advance for practical fa rm use.

Yo u rs sincere ly

P rofessor Graham JellisD i rector of Research & Deve l o p m e n t

Contents

Section Page

Grain marketing 4

Sampling and analysis 5

Milling wheat 6

Malting barley 8

Feed grains 10

The sampling process 12

Sampling equipment 14

Moisture meters 16

Sampling protocols

ex-trailer 18

ex-drier 20

Contacts & further reading 22

The Home-Grown Cereals Authority (HGCA) has prov i d e d

funding for the projects on which this guide is based but has not

conducted the re s e a rch or written this guide.While the authors

h ave wo r ked on the best information available to them,neither the

H G CA nor the authors shall in any event be liable for any loss,

damage or injury how s o ever suffe red dire c t ly or indire c t ly in

relation to the guide or the re s e a rch on which it is based.

R e fe rence herein to trade names and pro p r i e t a ry pro d u c t s

without stating that they are protected does not imply they may be

re g a rded as unprotected and thus free for general use.N o

endorsement of named products is intended, nor is any criticism

implied of other alternative, but unnamed pro d u c t s .

Introduction

3

Know what you have harvested

Know what you have sold

Manage what you have stored

• prepare store

• cool grain

• dry grain

• monitor

4

YES

• Segregate by variety and quality tosatisfy existing contracts first.

• Agree fallbacks with buyers beforesigning contracts in case things gowrong.

NO

• If concerned, seek less demandingmarkets.

• Don’t sell on price alone – be confidentyou can meet the specifications.

• Agree fallbacks with buyers beforesigning contracts.

Sampling and analysis

• Determine your harvest quality based on representative samples andaccurate analysis.

Does grain meet the specification of target markets?

Market planning begins

• Find out what your local buyers want.

• Compare potential premiums against additional growing costs.

• Match the varieties you sow to local market needs where possible.

• Plan sales to manage risk and meet cashflow requirements.

• Consider fixing quality premiums on a proportion of the crop.

Grain marketingIn a difficult marketplace, careful planning – basedon known crop quality – helps to achieve budgetedprice levels.An effective plan begins pre-drilling andtackles both marketing and price management.

At harvest

Before harvest

Marketing on sample resultsAt harvest,quality is determined by accurate samplingand analysis. Grain is marketed to maximise anypremiums by matching sample quality to the mostappropriate buyer.

Top prices must be balanced against risk of rejection.Be cautious of sending variable quality grain to distantor demanding buyers. Agree allowance charges withbuyers for grain below specification before signingcontracts.Budget realistically for deductions andrejections.

Pricing to meet objectivesDespite good sampling and analysis growers remainexposed to the underlying volatility of feed grain prices.All the effort of producing a premium grain crop for a£3/t premium can be wiped out by the underlying feedprice falling £10/t.This reinforces the need for coherentprice management.

Where storage can gain no other income,storingforward as far as possible may maximise returns.However, stored grain is exposed to price volatility.Selling forward, rather than relying on spot marketprices, reduces risk. Alternatively, price insurance usinggrain options protects unpriced grain in store.

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Farmers are an essential link in the ‘grain chain’ that, at each stage,i n c re a s i n g ly demands evidence of quality contro l .T h e re are seve r a lc o m p o n e n t s .Assurance schemes

M a ny buyers demand traceability. Membership of schemes – such as A s s u red CombinableC rops Scheme (AC C S ) , Farm A s s u red British Beef and Lamb (FA B B L ) , Genesis QA andScottish Quality Cereals (SQC) – provides this.

Feed compounders belonging to the UKASTA Feed Assurance Scheme (UFAS) re q u i re thatall grain they use must come from assured farms, with Grain Passports accompanying alld e l i ve r i e s . Most end-users also re q u i re the re l evant harvest year sticke r.

Millers and maltsters re q u i re a Po s t - H a rvest Pesticide Declaration form with eve ry load.

I n t a ke testsBasic quality parameters are tested at intake.To achieve efficient turn-around of lorr i e s ,results have to be available within 20-30 minu t e s .R apid secondary methods are pre fe rre dto more time-consuming primary tests.

B u yers depend on specialised equipment fo rs e c o n d a ry tests. For example, millers uses everal tests based on near infrared re f l e c t a n c eor transmittance (NIR or NIT) with ground orwhole grain re s p e c t i ve ly.

C a l i b r a t i o n , the relationship between re s u l t sf rom primary and secondary methods, i sestablished by re fe rence testing hundreds ofsamples and regular performance checks.

Quality control at intakeAssuming that re p re s e n t a t i ve samples aret a ke n , tests must achieve high, re p ro d u c i b l es t a n d a rd s .Training and competency checks aimto minimise inaccuracies caused by operator,equipment or re a g e n t s .We l l - d o c u m e n t e d ,validated methods are used with contro lsamples to monitor day - t o - d ay perfo r m a n c e.

● Sample grain correctly.

● Sell on the basis ofsampling and analysisresults, not just on price.

● Make the most of existingstores by selling grainforward before storage.

ACTION:

Checks on quality

Sampling and analysisRepresentative sampling and accurate analysis ensuresthat you know the quality of your harvested grain andthat you sell it to the most appropriate buyers.

Use sample results to optimise returns

Representativesamples,accuratelyanalysed, form thebasis of any salescampaign.Resultsallow grain to besegregated by qualityand variety.Producers can matchgrain batches tobuyers’specificneeds.

Each year poorsampling and analysiscost the industryaround £2.5 millionFailure to market the rightspecification of grain results in loss of quality premiums,additional haulage andadministration charges.Thesecosts have risen sharplycompared to the grain priceand can make the dif ferencebetween profit and loss.

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Moisture contentWheat quality is threatened when the moisturecontent of stored g r ain exceeds 15%.There is ar isk of infestation and mould as well asmycotoxin formation,all of which can lead torejection.

Specific weightThin,shrivelled grain will not mill to produceadequate amounts of clean,white flour.

The specific weight test measures the weight ofgrain – in kilog rammes – that can be packedinto a cylinder of fixed volume,normally 1 litre,and indicates g rain filling.

Screenings and admixtureScreenings are undersized g rains and admixtur ecomprises impurities,eg chaf f, weed seeds andearth,which must be removed before millingmarketable flour. Screenings and admixtur erepresent a loss to the miller, so a maximum of2% is normally allo wed.

Screenings and admixture are measured usingstandard slotted 3.5 mm and 2 mm sieves.

VarietyWheat varieties are categorised by nabimGroups 1 to 4.Groups 1 and 2 are used formost breadmaking g rists while Group 3 is usedfor a range of biscuit,cake and batter flours.

Protein contentP rotein content is specified for all bake r y f l o u r sand is a key par t of t he contra c t . For mo stb re admaking f l o u r, wheat wi th a prot ein c ont en tab ove 13% dr y matter, i s pre fe r re d . I f pro t e i nc ont ent cannot be ach i e ved using home- grow nw h e a t ,i m p o rted high protein whea t or whea tglute n can be a dded in. For most bis cuits an dc a ke s , gluten fo r mation is not re q u i red andmu ch lower protein f l o u rs may be used .

Protein qualityWhen wetted,during dough making,some ofthe proteins in wheat flour form a visco-elasticsubstance – gluten.This can hold gas producedduring fermentation and supports the starchand bran producing a typical well-risen UK loaf.

The amount and quality of gluten producedindicates potential performance.No fixedthreshold exists.

Milling wheat –quality criteria and tests

While almost any wheat canbe milled, millers produce awide range of flours withspecifications tightly defined bybakers for each product.

Millers analyse and thensegregate each batch of wheatto meet the quality theircustomers require for eachgrist or blend.

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Hagberg Falling NumberLow Hagberg indicates high enzyme activityand onset of sprouting. A threshold of 250seconds is used for breadmaking wheat andsamples with low Hagberg are rejected.LowHagberg wheat produces bread with a darkcrust colour and a weak,sticky crumb thatcannot be sliced.

The Hagberg test is used world-wide.It measures the time,in seconds,a plunger takesto descend through aheated mixture of gr oundgrain and water. The testprovides an indirectestimate of alpha-amylase activity.

Moulds, damaged grain and odoursVisual examination assesses g rain for moulds,Fusarium (pink g rains) and particularly er got.Checks are made for live insects and graindamaged by insects.

Experienced staff also assess grain for unusualodours.“Mustiness”or “chemical”odour sindicate stora ge problems.

Individual companies set their own criteria forthese assessments.

Grain hardnessGrain hardness is a k e y variety trait for milling.Hard and soft wheats have dif ferent processingrequirements and end-uses.The hard wheatsused for breadmaking must absorb suf ficientwater during dough making.Soft wheats arepreferred for biscuits as much added liquid isbaked out to produce a crisp product.

By crushing individual g rains within a SingleKernel Characterisation System (SKCS)instrument,the miller can check grain hardnessand identify mixtures of hard and soft varieties.Near infrared calibrations,based on SKCS,canrapidly separate hard and soft wheat samples.

Important parameters

Characteristic Farmer test Intake test Buyer response

Moisture content yes yes price deduction or rejection

Specific weight yes yes price deduction or rejection

Screenings and admixture yes yes price deduction

Variety no yes price deduction or rejection

Protein quality no yes price deduction or rejection

Protein content sometimes yes rejection

Hagberg Falling Number sometimes yes price deduction or rejection for breadmaking

Moulds, damaged grain no yes price deduction or rejectionand odours

Grain hardness sometimes yes price deduction or rejection

Visit the nabim website at www.nabim.org.uk

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Moisture contentAbove 14% moisture content, grain cannot besafely stored,while above 15% priceadjustments based on moisture content alonemay be triggered.UK maltsters usually dry to12% for long-term storage,but make no dryingcharge to suppliers below 19% moisturecontent.

Grain size, screenings and admixtureBarley is screened before processing to removesmall grains,which will not process properlyand give fermentable sugars.

A series of sieves is used to determine the grainsize of each load.

Screenings are undersized grains andimpurities,eg chaff and weed seeds,whichmust be removed before malting.Screeningsrepresent a loss to the maltster, so a maximumfigure is specified by the buyer.

Undersized grains and impurities are measuredusing standard slotted sieves of 2.5 mm and2.25 mm. Admixture is a contamination (egstones,dirt and foreign bodies) and a buyertypically allows a 2% maximum.The grain buyerwill define the standard used in the graincontract.

Grain damageKernels damaged, by skinning or splitting forexample,will allow nutrients to leak out duringmalting.This encourages infection and leads topoor extract yields.

Insect damage will impair both viability andextract yield.It also encourages mould infectionduring storage.

VarietyMaltsters require specific varieties suitable fortheir customers. Trained staff can identify grainby variety using visual inspection.In cases ofdoubt,laboratory testing of protein or DNA“fingerprints”can be used.

Viability Malting depends on grain germinating undercontrolled conditions,so grain must be fullyviable.The threshold viability for acceptance isa minimum of 98% germination.

Maltsters use barley ofdifferent specifications toproduce a range of malts. Forgrowers, key characteristicsare variety and the range ofgrain nitrogen percentage.

Maltsters test barley beforepurchase to assess suitability.Most tests are carried out atintake to ensure loads matchthe quality criteria.

Malting barley –quality criteria and tests

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Maltsters use a staining test. This rapidly measuresviability (known as germinative capacity) and indicatespre-germinated grains.

Grain that fails to germinate does not produceenzymes during malting.The resultant maltcauses processing problems.It reduces breweryor distillery throughput,and gives poor quality,cloudy beers.

Pre-germinated grains can die during steeping(the first stage of malting) or lead to mouldgrowth in malting,both of which causeproblems in brewery or distiller y.

NitrogenExcessive protein content can impair processingin maltings and breweries.Protein replacesstarch within grain and reduces alcohol yield.However, some protein is necessary for yeastgrowth and beer foam.

Protein is measured by assessing the totalnitrogen (TN) content of grain.Testing mainlyuses the Dumas method,which has replacedKjeldahl.Rapid assessments can also be madeusing near-infra-red spectroscopy. All give resultsaccurate to +/- 0.05%.

Mould, discolouration and food safetyGrain can be discoloured by “weathering”,ormould infection,which can depress viability andlead to contamination with toxins.

Any mould or “nose”will result in rejection.

Malting barley must comply with legal limits forcontaminants in food products.The GrainPassport is an important safeguard.Maltsterscheck random samples for pesticides,whileregular surveys check for other contaminants,eg mycotoxins and lead.

Important parameters

Characteristic Farmer test Intake test Buyer response

Moisture content yes yes price deduction or rejection

Grain size, screenings yes yes price deduction or rejectionand admixture

Grain damage no yes price deduction or rejection

Variety no yes price deduction or rejection

Viability no yes rejection

Nitrogen no yes price deduction or rejection

Mould, discolouration and food safety no yes rejection

Typical specifications● Most brewers require a TN of 1.55-1.85%.

● Distillers with pot stills and traditional alebrewers may need even lower N.

● Some brewers of export lager, using starch-rich adjuncts, require a TN of 1.8-1.85%.

Visit the MAGB web site at www.ukmalt.com

Wheat and barley are the main cereals used for animalfeeds. Feed compounders are becoming increasinglydiscerning about the cereals theyseek.While the aim is topurchase grain of high nutritionalvalue, there are no definitiveintake tests at present.

The industry also seeks grainthat is fresh and clean –important to satisfy codes ofpractice with respect toSalmonella and due diligence. Itmust be safe to store in the feedmill.

Most intake tests apply to allgrains for all livestock species.

Feed grains –quality criteria and tests

Moisture contentGrain moisture content is always measured onintake.Many feed merchants regard it as themost important assessment.It is seen as a verygood indicator of quality for animal feeding.High moisture content may indicate poorstorage and possible future problems,such asmould growth or sprouting,which may impairquality.

Grain,which is received above 15% maximummoisture content,may be rejected.

Specific weightAlthough quick and easy, the relevance of thistest as an indicator of grain quality for livestockis debatable.However, the industry has manyyears’ experience and continues to use it.Moresuitable indicators are needed.

Grain contracts set out required specificweight.Typical industry standards are72 kg/hl for wheat and 63 kg/hl for barley.Grain failing to meet specific standards isusually rejected,although some companiesoperate allowance schemes.

Moulds, admixtures and odoursInitially, grain is assessed for moulds,Fusarium (pink grains) and,particularly,

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ergot – which often collects on the top of aload.Ergots may not be detected by sampling.Other checks include insects or mites,admixtures of weed seeds,straw, chaff andforeign material including stones,broken grains,sprouted grains and animal or bird droppings.

The presence of any of these maylead to rejection and cert a i n lyp rice re d u c t i o n s .T h edetection of any ergo t ,F u s a rium or animald roppings means automaticrejection with no tolera n c e s .

Grain is also assessed for unusual odours byexperienced staff and by comparison withuntainted grain.Smells such as “mustiness”and“chemical”indicate storage problems.

Individual companies set their own standardsfor qualitative tests.Tolerances may varyaccording to the mill’s specific requirements.

Food safetyFeed grains must comply with legal limits forcontaminants in food products.The GrainPassport is an important safeguard.

Chemical analysisAlthough not conducted at intake, chemicalanalysis of grain allows feed compounders toadjust raw material matrices.Such analysis isnot normally relevant to grain producers.

Protein, fibre and ash are, by law, declared oncompound feeds.Therefore, feed compoundersneed to know the contents of theseconstituents in raw materials.

Whilst protein,calculated from nitrogencontent,is important for suppliers of animalfeed,a contract figure is rarely imposed ongrain suppliers.

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Important parameters

Characteristic Farmer test Intake test Buyer response

Moisture content yes yes price deduction or rejection

Specific weight sometimes yes price deduction or rejection

Moulds, admixtures no yes price deduction or rejectionand odours

Variety no no likely to become important

Chemical analysis no no none (tests carried out after intake)

British Poultry Council website – www.poultry.uk.com

MLC website – www.mlc.org.uk

National Pig Association website –www.npa-uk.net

UKASTA website – www.ukasta.org.uk

HARVEST

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The sampling pro c e s sOPTION 1:

ON-FLOOR DRYING

OPTION 2:

HIGH T E M P E R ATURE DRY I N G

S4

18% m.c.

17% m.c.

15% m.c.

13% m.c.

A1

A2

A3

A4

S3

Key:

Grain loads

Samples taken S1

A1

SAMPLING – EX-TRAILER(Take at least one sample from each trailer)

Sample flow with pelican sampler.or

Spear at least three samples from the tipped heap.

S4

HARVEST

13% m.c.

15% m.c.

17% m.c.

18% m.c.

S1A1

A2

A3

A4

S2

S3

PREPARATION Have all the equipment necessary forsampling – sample bags, boxes, recordsheets, spears etc – ready before harvestcommences.

S1

S2

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SAMPLING – EX-DRYERSample grain. Measure moisture contentfrequently – re-dry if necessary.

SUB-SAMPLE(for analysis)

COMPLETERECORD

SUB-SAMPLE(to retain)

STORE Composite sample represents identified loads in bulk or bin.

S5

S6

STORE with on-floor drying – Compositesample represents identified loads in bulk or bin.

COMPOSITE SAMPLE

Blend individual sub-samples

M E A S U R EM O I S T U R ECONTENT

A N DT E M P E R AT U R E

OF EAC HS A M P L E

S6

S5

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1.Containers for composite samples

Use plastic tubs or boxes,at least 10 litrecapacity with lids, kept specifically forsampling.Many retail outlets supply these at amodest cost.

Self-adhesive labels for containers are useful.

2. Site plan

Draw up a clear plan of the grain storage siteshowing all areas used to store grain.

Floor store plans should be divided into baysand each bay allocated a number and/or letter.

Give each bin an identification number.

Ideally, store each batch of 50 tonnes or less inan identifiable area.

3.Samplescoop

Use a litre plasticjug,obtainablefrom mostkitchenwareretailers, keptspecifically forsampling.

4. Pelican sampler

This consists of a rectangular box with an opentop.It can be easily constructed from woodenbattens and 5 mm plywood,mounted on a 1.5 m handle.

1.5 m5 cm

10 cm

20 cm

Sampling equipment

15

5. Grain spear

Ideally use a modern, multi-aperture spear, atleast 1.5 m long,capable of being opened andclosed by the operator. Such spears are emptiedthrough a single orifice,usually in the handle,into a container.

Spears that only take single samples must beinserted several times at different depths ateach point to collect a proper sample.Takeshallow samples first.

6. Diverter sampler

One way to sample grain ex-drier is to set up a simple“diverter sampler”. An angled,perforated tube is insertedinto the grain flow to bleed offa steady stream of grain.Setperforations at an angle tograin flow to avoid clogging.Rotating the tube adjusts theflow of grain sample.

7. Bags for merchantsamples

Use new plastic bags of at least 1kg capacity.Self-sealing bags with printed white areas for labels are very convenient.Label with an indelible marker pen.Alternatively, use a self-adhesive label.

Grain buyers often supply bags.

SuppliersAllied Grain (South) C h u rch LaneG o d m e rsham C a n t e r b u ry CT4 7DSTe l : 01227 731161 Fa x : 01227 731157E - m a i l :s p e a rs @ a l l i e d s o u t h . c o . u k

Pneumac 2 Benton Stre e tH a d l e i g hIP7 5ATTe l : 01473 822196 Fa x : 01473 827983E - m a i l :p n e u m a c s a l e s @ p l a n t - p a rt s . c o m

Kramp AshurstS t ratton Business Pa rk London Road B i g g l e swade SG18 8QBTe l : 01767 602600 Fa x : 01767 602620 E - m a i l : rya n . ri ch a rd @ k ra m p o n l i n e . c o m

Bearwell International Systems125 St Mary's RoadM a rket Harboro u g hLE16 7DTTe l : 01858 410096Fa x : 01858 410162E - m a i l :b e a r we l l @ h o t m a i l . c o m

F a rm - Te c3d Larpool Lane Industrial EstateW h i t byYO22 4LXTe l : 01947 825160Fa x : 01947 821372E - m a i l :s a l e s @ fa rm - t e c . c o . u k

GE Protimeter Meter HouseFieldhouse LaneM a r l ow SL7 1LWTe l : 01628 472722Fa x : 01628 474312E - m a i l :m o i s t u re @ p ro t i m e t e r.com

RDS Technology C i rencester Road M i n ch i n h a m p t o nS t ro u dGL6 9BHTe l : 01453 733300Fa x : 01453 733311E - m a i l :i n fo @ rd s t e c . c o m

Te k p ro Samplex Wi l l ow Pa rkN o rth Walsham NR28 0BDTe l : 01692 500202Fa x : 01692 404955E - m a i l : Jo h n B @ s a m p l ex.co.uk

Sinar Te c h n o l o g yUnit 6C raven Court Stanhope Road C a m b e r l ey GU15 3BSTe l : 01276 671620Fa x : 01276 671640E - m a i l :o ffi c e @ s i n a r. c o . u k

Moisture meters – use and maintenance

16

Moisture meters are used to estimate themoisture content of g rain samples taken tor epresent the bulk.This helps the grower:

• manage drying and energ y costs

• store grain at optimum moisture content(<14%) to a void spoila ge

• maximise crop returns. Costly rejections ordiscounts are a voided if the a verage meterreading of delivered bulk g rain meetscontract specification (with a mar gin forer ror).

How moisture meters work

Moisture meters measure an electrical propertythat varies with moisture content.

• Resistance instruments use a groundsample and tend to be small.

• Capacitance meters use whole grain andare usually larger.

Moisture meter manufacturers pr ovidecalibrations by comparing the meter’ selectrical measurement with actual moisturecontent determined by oven tests on samplesof wheat,barley, oilseed rape etc.

In the laborator y, moisture content isdetermined by drying coarsely ground cerealgrain for two hours at 130ºC in a special ovenand then measuring weight loss.The method isslow but accurate if the correct equipment andprocedures are used.

Meter accuracy depends on the quality ofcalibration and instrument maintenance.

Calibration

The best calibrations use large and varied datasets. For standard calibrations,se veral hundredsof g rain samples representing a wide range ofmoisture contents and varieties over se veralyears may be used.

For special calibrations,eg moisture contentex-grain drier, specific samples ensur ecompatibility between calibration and testmaterial.(Consult the manufacturer todetermine the basis of calibrations in yourinstrument.)

Moisture content, one of themost important characteristicsfor grain buyers and sellers,features in all contracts. Highmoisture content can result inspoilage and incur deductions,even rejection.

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● Perform any checks specified by the manufacturer before use.

● Use a representative sample. Remove chaff, straw, immature grains etc.

● Minimise temperature differences between sample and instrument to avoidcondensation on grain or meter.

● Test at a constant temperature, ideally 20±2ºC.

● Clean meter after use. Remove any whole or ground grains.

● Regularly check and record instrument performance with samples of knownmoisture content.

Calibration may be correct,offset,skewed or curved.Incorrect moisture calibrations will have an impact onmeter readings.In this example, using 16% oven moisturecontent,incorrectly calibrated instruments can give valuesbetween 16.1% and 16.9%.

Where calibration is skewed or curved,consult themanufacturer for re-calibration.Instrument instructionmanuals normally contain information to enable theoperator to correct for offset.Many suppliers offer a pre-harvest instrument performance check.This should includevalidation of standard calibrations.

This is needed to ensure accuracy of calibrations for eachcommodity and can be done by comparing meter readingsfor 10-20 samples with known oven moisture contents.

Regular checking

ACTION:

Moisture meter guidelines, HGCA (2000)

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1. Equipment

Keep equipment clean and only use for sampling andstoring grain samples.

1.1.Samplers

• Pelican sampler

• 1 litre plastic jug

• Sampling spear (to collect about 750 g grain from one or several insertions).Preferably use a multi-aperture spearthat can be opened and closed by the operator to collect grain from several depths at each insertion.

1.2.Containers

• 10 litre or larger plastic drums,boxes or tubs with lids.

• Sample bags of about 1 kg capacity – which can be effectively sealed and labelled.

Establish a system to relate samples to specific bins of grain or sections of a bulk store.Number bins and paint baynumbers on the walls of floor stores.Indicate these numbers on the site plan.

2. Collecting samples

Collect a sample of about 1 kg from the tailgate as trailers tip in the store.If trailer tips through a hatch in thetailgate,use a jug or pelican.If the whole tailgate is opened,only use the pelican.It may be safer to collect asample from the tipped heap with a spear.

2.1.Technical details

Sweep a plastic jug or pelican sampler across the grain flow from the trailer, so as to cut the stream of grain.Removethe jug or pelican as soon as full.Sample in a consistent manner. Avoid sampling first or last parts of the load.

Sample the grain after tipping by inserting the spear and removing a sample(s) from at least three positions.

Empty the jug,pelican or spear into a plastic container. Check moisture content and temperature of some grainfrom each individual sample first,if this container is used to build up a composite sample.Blend compositesamples thoroughly before sub-sampling.

2.2.Testing

Measure the moisture content of each sample to give guidance on intake moisture and the need for drying.

If the meter uses a large,un-ground sample,tip the grain back into the main sample after testing.Measure thetemperature of the grain to indicate the need for in-store cooling.

The aim of taking a sampleor series of samples is togive a fair representation ofa batch or bulk to allowassessment of quality, valueand storage potential.Sampling grain going intostore is not a substitute forsampling during storage.

Photo to come trailer tipping

Sampling protocol – ex-trailer

Sampling protocol – ex-trailer Version One — January 2003

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3. Frequency of sampling

3.1.Storage potential

Assess samples from sufficient incoming loads for moisture and temperature to allow proper decisions to be madeabout drying and cooling.This may mean testing every load as moistures often change during the day.

3.2.Commercial sample

Produce one composite sample to represent each bin or each identified section or bay within a bulk store.

Start a new composite sample whenever moving to a new part of the store or taking grain from a dif ferent field.

Make up at least one composite sample for each 50 tonnes of grain irrespective of bin or bay size.

Samples best representing commercial value are made up from sub-samples taken as every trailer enters the store.Sub-sampling frequency depends upon intake variability.

4. Sample handling

Label the container holding the composite sample clearly outside and inside.Make sure that the sample can be relatedto an identifiable batch of grain in the store (bin or section of a store).Make sure that the labels correspond to the site plan.

Close the container with a lid that will prevent rodent access,stop contamination by dust or other grain and minimisemoisture loss.

If grain in the store is moved,amend the site plan and ensure that the sample label still corresponds to the correctbatch of grain.Moving the grain may also present an ideal time to re-sample and produce new composite samples.

Store the containers in the grain store under the same conditions as the grain they represent.

4.1.Sample storage

Samples with a moisture content of >14.5% may deteriorate during long-term storage;those with high moisturecontents will go mouldy. Dry those with moisture content >14%, by spreading thinly on a tray in a warm dry room for24-48 hours and label as “dried”. Alternatively, send samples of wet grain for analysis without delay.

5. Extracting commercial samples

Mix the composite sample thoroughly before extracting any samples for buyers.

After mixing,tip the grain onto a clean plastic sheet and divide up using a clean board into halves,quarters andeighths,until the correct amount is obtained for the buyer’s sample.

Carefully remove all the buyer’s sample (about 1 kg) from the sheet,including all fine material and transfer to a plasticbag.

Seal and label bag.

It is worth measuring the moisture of this sample as, by doing so,a comparison between the farm and merchant’smoisture meter will be obtained.

6. Labelling

L abel info rmation for composite samples should incl u d e :date of collection; va ri e t y ;m o i s t u re content(s); location of grain re p resented by the sample:eg Bin 3, or Shed 1: left bay 2.

Labels on buyer’s samples should include:farm address and any other identity codes;quality scheme membership number (attach an assurance scheme identitysticker to the sample bag);location of grain represented by the sample (it must be possible for the buyer to be ableto identify the location of the batch of grain covered by the sample.In some cases this may differ from the farmoffice address);date of harvest;tonnes represented by sample; variety;and moisture content.

7. Safety

There are risks associated with the collection of samples. Assess the risks involved with specific tasks and locations,and take steps to minimise them.

Specific risks include:

• working near moving equipment

• conveying equipment – augers and elevators – must be guarded

• being engulfed by grain – never stand or walk on moving grain

• grain dust – wear a dust mask

• grain pits – must be covered with a protective grill.

When handling treated grain,personal protective clothing must be worn,eg gloves and masks.

Working at the back of trailers during tipping can be dangerous because of the risk of being hit by the swingingtailgate or by being engulfed by grain.Only approach the rear of the trailer if it safe to do so. Always ensure that thetrailer driver knows the sampler is present,especially when the trailer has a hydraulic tailgate.

Sampling protocol – ex-trailer Version One — January 2003

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1. Equipment

Keep equipment clean and only use for sampling and storinggrain samples.

1.1.Samplers

• Pelican sampler

• 1 litre plastic jug

• Sampling spear (to collect about 750 g grain from one or several insertions).Preferably use a multi-aperture spearthat can be opened and closed by the operator to collect grain from several depths at each insertion.

• Diverter sampler inserted permanently into drier input and output flows.

1.2.Containers

• 10 litre or larger plastic drums,boxes or tubs with lids

• Sample bags of about 1 kg capacity – which can be effectively sealed and labelled.

Establish a system to relate samples to specific bins of grain or sections of a bulk store.Number bins and paint baynumbers on the walls of floor stores.Indicate these numbers on the site plan.

2. Collecting samples

Sample collection site depends upon facilities.Options include drier outflow, conveyor discharge or point of graindischarge into bin or floor store.Use samples collected as grain enters drier to assess drier performance.The best andsafest option is a permanent diverter sampler in the drier outflow.

2.1. Technical details

Sweep a plastic jug or pelican sampler across the grain flow from either conveyor or spout,so as to cut the stream ofgrain.Remove the jug or pelican as soon as full.Sample in a consistent manner.

Sample the grain after tipping by inserting the spear and removing a sample(s),from at least three positions.

Empty the jug,pelican or spear into a plastic container. Check moisture content and temperature of some grainfrom each individual sample first,if this container is used to build up a composite sample.Blend compositesamples thoroughly before sub-sampling.

If using a diverter sampler, allow the grain to fall directly into the plastic container. Collect sub-samples at regularintervals and measure moisture content and temperature.

2.2.Testing

Measure the moisture content of each sample to confirm that final moisture content is low enough for safe storage.

If the test meter uses a large,un-ground sample,tip the grain back into the main sample after testing.Measure thetemperature of the grain to indicate the need for in-store cooling.

The aim of taking a sample orseries of samples is to give a fairrepresentation of a batch orbulk to allow assessment ofquality, value and storagepotential. Sampling grain goinginto store is not a substitute forsampling during storage.

Sampling protocol – ex-drier

Sampling protocol – ex-drier Version One — January 2003

21

Sampling protocol – ex-drier Version One — January 2003

3. Frequency of sampling

Sampling frequency depends on drier type,whether batch or continuous flow.

3.1.Storage potential

Measure temperature and moisture content of samples regularly. Base sampling frequency on grain moisture contentbefore drying.Sample grain several times if moisture content varies within the bulk pre-drying.

3.2.Commercial sample

The best samples to represent commercial value comprise many sub-samples taken at relatively short intervals asgrain is discharged from the drier.

For batch driers,collect several samples (at least 1/t of grain in the drier) as the dried batch is discharged.

Combine samples from several batches into a single composite sample,provided the grain represented by thesample is stored in an identified section of the store.

Produce one composite sample to represent each bin or each identified section or bay within a bulk store.

Start a new composite sample whenever moving to a new part of the store or taking grain from a dif ferent field.

Make up at least one composite sample for each 50 tonnes of grain irrespective of bin or bay size.

4. Sample handling

Label the container holding the composite sample clearly outside and inside.Make sure that the sample can berelated to an identifiable batch of grain in the store (bin or section of a store).Make sure that the labels correspond tothe site plan.

Close the container with a lid that will prevent rodent access,stop contamination by dust or other grain and minimisemoisture loss.

If grain in the store is moved,amend the site plan and ensure that the sample label still corresponds to the correctbatch of grain.Moving the grain may also present an ideal time to re-sample and produce new composite samples.

Store the containers in the grain store under the same conditions as the grain they represent.

5. Extracting commercial samples

Mix the composite sample thoroughly before extracting any samples for buyers.

After mixing,tip the grain onto a clean plastic sheet and divide up using a clean board into halves,quarters andeighths,until the correct amount is obtained for the buyer’s sample.

Carefully remove all the buyer’s sample (about 1 kg) from the sheet,including all fine material and transfer to a plastic bag

Seal and label bag.

It is worth measuring the moisture of this sample as, by doing so,a comparison between the farm and merchant’smoisture meter will be obtained.

6. Labelling

Label information for composite samples should include:date of collection; variety;moisture content(s);location of grain represented by the sample:eg Bin 3,or Shed 1:leftbay 2.

Labels on buyer’s samples should include:farm address and any other identity codes;quality scheme membership number (attach an assurance schemeidentity sticker to the sample bag);location of grain represented by the sample (it must be possible for the buyer tobe able to identify the location of the batch of grain covered by the sample.In some cases this may differ from thefarm office address);date of harvest;tonnes represented by sample; variety;and moisture content.

7. Safety

There are risks associated with the collection of samples.Assess the risks involved with specific tasks and locations,and take steps to minimise them.

Specific risks include:

• working near moving equipment

• conveying equipment – augers and elevators – must be guarded.

• being engulfed by grain. Never stand or walk on moving grain.

• drier exhaust fumes.

• grain dust – wear a dust mask.

When handling treated grain,personal protective clothing must be worn,eg gloves and masks.

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Contacts & f u rther re a d i n g

Contacts

ACCS – Assured CombinableCrops Schemec/o CMI Certification LtdThe Business ParkLong HanboroughOxfordOX29 8LHTel:01993 885610Fax:01993 885611E-mail:[email protected]

BRi – Brewing ResearchInternationalLyttel HallNutfieldSurreyRH1 4HYTel:01737 822272Fax:01737 822747E-mail:[email protected]

BPC – British Poultry CouncilEuropoint House5 Lavington StreetLondon SE1 0NZTel:020 7202 4760Fax:020 7928 6366E-mail:[email protected]

CCFRA – Campden &Chorleywood Food ResearchAssociationChipping Campden GloucestershireGL55 6LDTel:01386 842000E-mail: [email protected]

CSL – Central Science LaboratorySand HuttonYorkY04 1LZTel:01904 462000Fax:01904 462111E-mail:[email protected]

FABBL – Farm Assured BritishBeef and LambPO Box 165 Winterhill HouseSnowdon DriveMilton KeynesMK6 1PBTel:01908 231642Fax:01908 844355E - m a i l :i n fo @ fabbl . c o . u k

FAC – Federation of AgriculturalCo-operatives(see NFU)

GAFTA – Grain and Feed TradeAssociationGafta House6 Chapel CourtChapel PlaceLondon EC2A 3DQTel:020 7814 9666Fax:020 7814 8383E-mail:[email protected]

Genesis QARyknield HouseAlrewasBurton on TrentDE13 7ABTel:01283 791400Fax:01283 791500E-mail:[email protected]

MAGB – Maltsters Association ofGreat Britain31b Castle GateNewark on TrentNottinghamshireNG24 1AZTel:01636 700781Fax:01636 701836E-mail:[email protected]

Meat & Livestock CommissionPO Box 44Winterhill HouseSnowdon DriveMilton KeynesMK6 1AX Tel:01908 677577Fax:01908 609221E-mail:[email protected]

nabim – National Association ofBritish and Irish Millers 21 Arlington StreetLondonSW1A 1RN Tel:020 7493 2521Fax:020 7493 6785E-mail:[email protected]

NFUAgriculture House164 Shaftesbury Avenue London WC2H 8HLTel:020 7331 7200Fax:020 7331 7313E-mail:[email protected]

NFUS – NFU of ScotlandThe Rural CentreWest MainsInglistonNewbridgeMidlothian EH28 8LTTel:0131 472 4000Fax:0131 472 4010E-mail:[email protected]

National Pig AssociationPO Box 29072 LondonWC2H 8QSTel:020 7331 7650Fax:020 7331 7630E-mail:[email protected]

23

Rural Payments AgencyKings House33 Kings RoadReadingRG1 3BUTel:0118 958 3626Fax:0118 959 7736E-mail:[email protected]

SQC – Scottish Quality CerealsRoyal Highland Centre10th AvenueInglistonEdinburghEH28 8NFTel:0131 335 6600Fax:0131 335 6601E-mail:[email protected]

UFU – Ulster Farmers Union475 Antrim RoadBelfastBT15 3DATel:028 9037 0222Fax:028 9037 1231E-mail:[email protected]

UKASTA – United KingdomAgricultural Supply TradeAssociation21 Arlington StreetLondonSW1A 1RN Tel:020 7495 9100Fax:020 7495 9150E-mail:[email protected]

Further reading

The grain storage guide, HGCA(1999) (revised 2002) free to HGCAlevy-payers,otherwise £25(to be revised in 2003)

Rodent control in agriculture - aguide, HGCA (2002) free to HGCAlevy-payers,otherwise £25

Moisture meter guidelines, HGCA(2000) free to HGCA levy-payers

Introductory guide to millingwheat, HGCA (2002) free to HGCAlevy-payers,otherwise £25

Introductory guide to maltingbarley, HGCA (2001) free to HGCAlevy-payers,otherwise £25

Topic Sheet No. 26 - Samplinggrain on-farm

A c k n ow l e d g m e n t sSection authors were: Julian Bell,HGCA economist;Dr Simon Hook,GSAP manager, HGCA;Mrs Susan Salmon,CCFRA;Dr Denise Baxter, BRi;Dr Julian Wiseman,University of Nottingham;Robin Wilkin,consultant.

HGCA is grateful to the many individuals who commented ond raft ve rsions of this guide incl u d i n g : Mairé Burn e t t ,B ri t i s hPo u l t ry Council;Rob Clare , A DA S ;R o ger Clark - M o n k s ; A n d rewC rag g , fa rm e r ; Alan Daley, G rampian Country Fo o d s ;B ru c eJo h n s o n ,G re e n c o re ; Jane Jo h n s o n , Genesis QA; Dr Jo n a t h a nK n i g h t ,I m p e rial College ; A rchie Lamont, G ra i n fa x ; Dr PhillipM o rra l l ,B a i rds Malt; I vor Murre l l ,M AG B ;M a rk Ringro s e ,B O C MPa u l s ; Pete Robson, M u n t o n s ; Paul Rooke ,U K A S TA ;H u g hS ch ry ve r, Allied Gra i n ; Damian Te s t a ,n ab i m ;D e i rd re We bb ,U K A S TA ;R i ch a rd W h i t l o ck , Banks Cargi l l ; Dr Ken Wi l d ey,C S L ;Trevor W ri g h t , Simpsons Malt.

It was edited by Dr Clive Edwards,HGCA and Geoff Dodgson,Chamberlain.

Design by Chamberlain.

The ‘Grain Sampling and Analysis Project’(GSAP) is co-funded by HM Treasury(Invest to Save Budget (ISB) project 720)through Defra Arable Crops Division and HGCA.

For information on HGCA services:

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© HGCA 2003