cork technical manual for the correct use of cork stoppers · Assoenologi Stefano Zaninotto Amorim...

cork technical manual for the correct use of cork stoppers

cork (cork) [prob – Du., LG. kork (whence G. kork) . Sp. alcorquecork sole of shoe, perh. of Arab. origin (see AL – pref.).]1. The bark or periderm of the cork-oak 1570. 2. Anythingmade of cork; … 3. The cork-tree or cork-oak (Quercussuber) 1601. 4. To stop (a bottle, etc.) with, or as with, a cork

cork technical manual for the correct use of cork stoppers

CoordinationValeria Mazzoleni Institute of Oenologyand Agro-food Engineering,Faculty of Agricultural Science,Università Cattolica del SacroCuore, Piacenza

Committee membersAndrea AcanforaColombin & figlio

Michele AddisSugherificio Molinas

M. Gabriella DallavalleMureddu Sugheri

Roberta DanziUIV (Unione Italiana Vini)

Maria Daria FumiFacoltà di Agraria Università Cattolica delSacro Cuore, Piacenza

Alessandro RuggeroSugherificio Ganau

Loris VazzolerAssoenologi

Stefano ZaninottoAmorim Cork Italia

Editorial coordinationNoesis Comunicazione, MilanoAntonella Nasini Sara Smedile

Graphic designMarina del Cinque

Technical and scientific committee:This manual has been producedwith the contribution of:Amorim Cork ItaliaColombin & figlioMureddu SugheriSugherificio GanauSugherificio Molinas

“Cork is part of our history andculture”, writes Helena Pereira inher latest book [1], and while thisnoted Portuguese cork researcheris referring to her own country here,it is a comment that also applies tomany other Mediterranean countries,including Italy. Her assertion iscorroborated by the discovery ofnumerous archaeological finds fromthe Roman and Greek periods andeven earlier, as well as byquotations from numerous ancientliterary works.

In the past, cork was exploited for itsthermal insulation properties,resistance to impact, flotation in waterand ability to seal recipients, and allthese uses remain virtually unchangedtoday, despite the progress that hasbeen made in the various fields ofhuman endeavour. The production ofcork closures for various types ofbeverage continues to be an importanteconomic driver in some countries. Inwinemaking, cork enjoyed a virtuallyunchallenged monopoly for centuriesuntil the development of alternativeclosure systems in recent decades.The success of cork in winemaking isexplained by the fact that the gradualindustrialisation of wineries starting in

the 18th Century revealed just howflexible this material is and how well itwas able to adapt to faster, moreprecise and increasingly highlyautomated bottling lines. Today the corkindustry has the at times difficult taskof transforming a natural material likecork so that it can be used in modernwineries and of guaranteeingperformance that preserves the qualityof the wine until bottles are opened. Toachieve this goal, cork stopperproducers need to introduceincreasingly strict controls in thevarious stages of production, but weshould also remember that corkstoppers perform their task best whenused in carefully controlled conditions.

The purpose of this Manual is to examinein detail how cork stoppers are used inthe wine-making industry, from deliveryand corking through to bottlesdistribution and consumption. Amplespace is devoted to examining possibleproblems relating to the use of corkclosures, their causes andtroubleshooting procedures to resolvethem. Troubleshooting information isprovided in table form for easy

consultation and use directly in wineries.All the aspects considered are discussedfor still, sparkling and semi-sparkling wines.This Manual draws on multidisciplinarycompetences in the cork and winemakingfields, and while addressed primarily to atechnical audience, it is also for studentsand producers who are looking forspecific information about the correctuse of cork closures in a single,comprehensive study.

THE VARIOUS TYPES OF CORK STOPPER

DELIVERY TO WINERY, STORAGE AND CONSERVATIONOF CORK STOPPERS BEFORE USE

USE OF CORK STOPPERS

CELLAR STORAGE OF BOTTLED WINES

TRASPORT, STORAGE BEFORE AND AFTER SALE,CONSUMPTION

TROUBLESHOOTING

BIBLIOGRAPHY

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THE VARIOUS TYPESOF CORK STOPPER

one-piece colmated natural corkstopper treated using cork dustand glue to eliminate surfacedefects

multi-piece or bonded naturalcork stopper comprising two ormore pieces of cork joinedtogether by glue. The cork isobtained from low thickness,slow-growing planks to producehigh density stoppers

agglomerated stopper (*) agglomerated stopper with discs(1+1, 0+1 or 0+2 depending on thenumber of discs and their positionin relation to the two ends of thecork stopper) (*)

new generation agglomeratedstopper, obtained by means of theagglutination of cork granulestreated with glue and thatcontains at least 75% corkgranules (by weight) (*)

one-piece natural cork stopper

The cork stoppers availableon the Italian market can beclassified as follows:

(*) these stoppers are also known as “technical cork stoppers”,in accordance with ISO 633:2007 Cork – Vocabulary

The choice of stopper is based on: • Characteristics including diameter/length/visual class,determined as described in“Nuovo Disciplinare sullemetodiche analitiche per ilcontrollo del tappo di sugheroad uso enologico” [2]

• Overpressure inside bottle, as follows:A) natural cork stopper (anytype), for still winesB) agglomerated stopper, forstill, semi-sparkling andsparkling winesC) agglomerated stopper withdiscs, for still (0+1 or 1+1),semi-sparkling and sparklingwines (with discs only on theend inside the bottle)

• Insertion line with respect to bottle mouth, as follows:A) Straight cork: insertion ofmaximum 1 mm sink, for stillor semi-sparkling wines

B) Mushroom shapedcorking: insertion of the corkto about half of its length,leading to the characteristicmushroom shape aftersecuring in place bymuselets, for semi-sparklingand sparkling wines.

Usual pressure inside bottleGenerally speaking, theoverpressure values inside thebottle (at 20°C) for the variouscategories of wine are:still and fortified wine: slight depression/overpressurecompared with atmosphericpressure, depending on thebottling system usedsemi-sparkling wine: internal overpressure between 1.5 and2.5 barsparkling wine: internal overpressure between 3.5 and6 bar.

•

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01Stopper | product obtained fromcork and/or agglomerated cork,made up of one or severalpieces and intended to sealbottles in order to preserve theircontents.

Multi-piece cork stopper | corkstopper made from several piecesof natural cork glued together.

Agglomerated cork stopper madeby extrusion/moulding (*) | corkstopper obtained by means of theagglutination of cork granules,with a granulometric sizebetween 0.25 and 0.8 mm, bondedwith flexible glue using a processof extrusion or moulding.

Agglomerated straight corkstopper with natural cork discs forstill and semi-sparkling wines |stopper having a body made ofagglomerated cork with one ormore natural cork discs glued onone or on both ends. Theagglomerate may be obtainedfrom treated cork granules.

DEFINITIONS (from the INTERNATIONAL CODEOF CORK STOPPERMANUFACTURING PRACTICE –C.E. Liège, 6th Edition, 2011)

FINISHED PRODUCTS

Agglomerated cork stopper withnatural cork discs for semisparkling and sparkling wines (*) |agglomerated cork stopper withone or more natural cork discsglued on one end.

Agglomerated cork stopper withnatural cork discs for traditionalmethod sparkling wines (*) |agglomerated cork stopper withone or more natural cork discsglued onto the same end. Thedisks may not be less than 4 mmthick and the combined height ofthe discs must be between 10 and13 mm. The agglomerate may beobtained from treated corkgranules.

(*) these stoppers are also knownas “technical cork stoppers”, inaccordance with ISO 633:2007Cork – Vocabulary

SEMI-FINISHED PRODUCTS

Body | natural cork cylinder madefrom one or more pieces, or fromagglomerated cork, and obtainedby extrusion or moulding

Granulated cork | cork fragmentsof variable size obtained by grindingprepared cork and/or by millingmanufactured cork stoppers orcork cut pieces, with dimensionsgenerally between 0,25 mm and 8mm, and already classified bygrain size and bulk density.

Disc | cylindrical piece of naturalcork with variable diameter andthickness, manufactured bycutting cork planks perpendicularly tothe growth rings.

Treated granulated cork |granulated cork produced with amethod that tends to improveorganoleptic neutrality and isused in the production of«agglomerated treated granulatedcork stoppers».

BOX A

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01Fine sparkling wine | producedlike sparkling wine from superiorquality wines (e.g. designatedorigin). Bottles have anoverpressure of ≥ 3.5 bar at 20° C.

Aromatic fine sparkling wine |produced using grape must orpartially fermented grape mustfrom specific aromatic varieties.This sparkling wine must have aneffective alcohol content of ≥ 6%vol. and a total content of ≥ 10%vol. Bottles have an overpressureof ≥ 3 bar at 20° C.

Semi-sparkling wine | producedwith an effective alcohol contentof ≥ 7% vol. and obtained fromwine with a total alcohol contentof ≥ 9% vol. Bottles have anoverpressure due to endogenousdissolved carbon dioxide ofbetween 1 and 2.5 bar at 20° C.

Gasified sparkling wine / gasifiedsemi-sparkling wine | producedby adding carbon dioxide to wine.Overpressure in bottles mustcomply with the values indicatedabove in the respective category.

Note: exclusions refer to variousP.D.O. and P.G.I. wines

Wine | produced exclusively fromthe total or partial alcoholicfermentation of fresh crushed oruncrushed grapes or grape must.Has a total alcohol content of ≤

15% by weight (with exclusions).

Fortified wine | produced frompartially fermented grape must orfrom … wine with the addition ofneutral wine-derived alcohols,distilled wine, concentrated grapemust … (with exclusions) …,having an effective alcoholcontent between 15 and 22% byvolume and a total alcohol contentby volume of ≥ 17.5% (withexclusions).

Sparkling wine | produced fromthe first or second alcoholicfermentation of fresh grapes,grape must or wine. Onuncorking, the carbon dioxideproduced derives exclusivelyfrom fermentation. The cuvéefrom which sparkling wine isproduced must have a totalalcohol content of ≥ 8.5% vol.Bottles have an over pressureof≥ 3 bar at 20°C.

WINEMAKING PRODUCTCATEGORIES (Attachment I to EuropeanCouncil Regulation no. 491/2009,25 May 2009)

BOX B

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• correspondence of the material delivered to the materialordered (type of cork, printingand quantity)

• quality controls performed according to the “NuovoDisciplinare sulle metodicheanalitiche per il controllo deltappo di sughero ad usoenologico” [2]

• check the level of quality agreedby supplier and customer.

Delivery of cork stoppers

When the cork stoppers are deliveredto the winery, the followingparameters must be checked:• conditions of the vehicles used, which must be dry, free ofodours and not also be carrying,together with cork stoppers,other material that may in someway contaminate them (e.g.paint, solvents, detergents, foodproducts with distinctivearomas, etc.)

• state of packaging, which must be sealed, undamaged and dryand placed on plastic pallets or HTtreated wooden pallets accordingto commercial agreementsdefined with the supplier

Cork stopper purchasing

Choose the most suitable corkbased on:• style of wine• wine pressure• shipment conditions• the internal diameter of the bottle neck. It should beremembered that not all bottlesare the same and that evenbottles of the same type (e.g.standard Bordeaux bottle), butof differing weights andproduced by diverse suppliers,may have a different internaldiameter

• the instructions and technical specification provided by thesupplier.

DELIVERY TO WINERYAND STORAGE OFCORKS BEFORE USE

CORKWOOD

Cork stopper with one or moreareas of suberose tissue whichhave not matured completely, inwhich cells have a translucentand brownish appearance. Duringstorage of planks, this tissuebecomes lighter in colour andshrinks, causing deformation.

INSECT GALERIES

Cork with one or more insectgaleries. Generally these holesextend along one growth ring andcan affect both the diameter andlength of the cork stopper entirelyor in part. The cork has two holeson the surface of the stopper.

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DRY YEAR

A woody discontinuity inside thesuberose tissue, caused by theinclusion in a layer of cork of theunderlying conducting cells(phloem tissue) as a result of aperiod of intense aridity; thisdiscontinuity may be almost total(in this case a dry year is thecause) or partial, generatingwoody nodules or inclusions.

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SOME CRITICAL DEFECTS IN CORK STOPPERS (8, 9)

BOXC

BLOWN CORK

A structural discontinuity in a yearof growth, generally caused whentrees loose all their leaves,causing the formation of one ormore layers of small, flat cells.Sometimes this defect is visiblemacroscopically in the form ofcracking on the lateral surface orends of the stopper, butsometimes it is completelyinvisible. The defect results intotal or partial detachment of thetwo layers at the site of thecracking.

LONGITUDINAL OR TRANSVERSALCRACKS

Corks with one or more openings ofirregular shape and length on thebackside. A crack can be longitudinalif it develops in vertically along theheight of the cork, or transversal if itdevelops horizontally.

Examples of blown corkExample of dry year in a one-piece corkExample of dry year in a sparklingwine cork (detail)Examples of corkwood corkExamples of insect galeriesExample of longitudinal crackingExample of transversal cracking

1/2)3)4)

5/6)7/8)9)10)

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• used exclusively for storingcork stoppers if possible, butin any case must nevercontain chemical substancesof any type (paint,hydrocarbons, cleaningproducts, vineyard treatmentproducts, etc.)

• cleaned using chlorine-free detergents

• free of wood or woody material (pallets, posts, planks, etc.)treated with chemicalsubstances and particularlywith halophenols

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Cork stopper storage

Packaged cork stoppers should neverbe left outdoors and immediatelytransferred to a proper indoorstorage area. This area must be:• clean, well-aired and dry• at the ideal temperature and relative humidity of 15-25°C and50-70% respectively (lowertemperatures down to 5°C areacceptable, as long as the corksare conditioned for at least 24hours at the optimumtemperature before use)

• free of odours which could contaminate the product

• we advise analysing the air in storage areas periodically tocheck for any chemicalpollutants (halophenols andhaloanisoles) in accordancewith current legislation

• we recommend painting walls with mould resistant paints andwhich do not releasesubstances responsible forsensory anomalies (StandardUNI 11021:2002)

• corks must always be stored in their original, sealed andundamaged bags (in theevent of opening forsampling purposes,containers must be resealedimmediately)

• the bags must be raised above ground and never exposed tosunlight, even through glass

• cork stoppers must be used before the date recommendedby the manufacturer

• stocks must be used on a FIFObasis (First In First Out)

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BOXD 1Class C:this class includes all non-conformities that affect filling lineproductivity:• Narrow necks (if they cause filling or corking problems)

• Bottles out of dimensional specifications

• Resistance to internal pressure out of specification

• Mixed bottles in pallet(the presence of only onedifferent container requires theentire delivery batch to betemporarily set aside. This non-conformity is managed bycommon agreement betweenthe parties)

Class B:this class includes all non-conformities which fail to ensurethe correct storage andconsumption of the wine • Edge cutting• Flat bubbles at mouth• Mouth parallelism in respect of maximum tolerance pursuant toCE.T.I.E. DT2 regulation (ifprecludes a correct corking)

• Out of vertical in respect of maximum tolerance pursuant toCE.T.I.E. regulation DT2 (ifprecludes correct corking)

• Crease on mouth• Internal profile of mouth out of specification

CORK STOPPERS USE

Bottles must be manufacturedwith glass suitable to contain foodproducts (type A sodium-calciumglass in accordance with theItalian Ministerial Decree dated21/03/1973, as amended) and incompliance as regards heavymetals with Legislative Decreeno. 22, dated 05/02/97 (ratifyingEuropean Council Directive 94/62,21/12/1994) as amended on19/02/2001 and 08/05/2006. The technical characteristics ofthe bottle and mouth andlimitations on the use ofcontainers are set out in thetechnical documents provided byeach glass manufacturer.The dimensions of the container mustbe as per the technical drawing.

The tolerances of diameter,height, verticality, and mouthparallelism must comply withCE.T.I.E. regulation DT2.The capacity of bottles“Measuring containers” mustcomply with the requirements ofDecree Law 451, 03/07/76 andLaw no. 416, 19/08/76.The official control method is setout in ISO 8106:2004.For use with sparkling wine, thebottles must be suitable andcertified for bottling wine with aninternal overpressure of ≥ 3,5 bar.For semi-sparkling wines, bottlesmust be suitable and certified forbottling with an internaloverpressure of between 1.5 and2.5 bar.

Bottle checksIn addition to the requirements given in Box D, bottles must also be freeof the defects defined in point 4.1.3 of the Technical Specification for thesupply of Standard Wine Bottles (Assovetro and Unionvini, 1st revision,November 2009) and specifically:

REQUIREMENTS OF BOTTLE (extract from the Technical Specification for the supply of Standard WineBottles, Assovetro and Unionvini, 1st revision, November 2009)

Preliminary corking machine checks

• Check that the jaws are in goodcondition and clean

• Ensure adequate cleaning of thecorking turret, the corkelevators and the feedinghoppers

• Check the point of maximum compression of the corking jaws(optimum diameter 15.5 mm)

• Maintain adequate cork orthogonality

• Check that the bottle advancingsystems are suitable for theused bottles

• Adjust the height of the corkinghead in accordance with thebottle used

• Check that the compensationspring, if present, is in goodcondition

• Check saturation systemoperation, if present

• Check vacuum systemoperation, if present

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System operating checks

Bottle filling: • Check the filling level and adjustif necessary based on fillingtemperature and/or subsequentheat treatment of the wine

• Check that there is no liquid layer in the section of the neckbetween cork and glass(essential in the case of fortifiedor dessert wines)

• Check for any pressure in thebottle due to transport gas (forstill wines)

• Check the depression value(for still wines)

• Check auto-level system operation, if present

Bottle corking:• Check that the cork is perfectly inserted into the compressionchamber and does not protrudeoutside it

• Check that the compressingsystem does not cause anydeformation or alteration to thecork structure

• Check the precise level of cork insertion (for straight corkstoppers bottling between 0 to 1mm range)

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1) Example of cork deformation caused by incorrect cork insertioninto the bottle

2) Example of sparkling wine cork deformation

3) Example of scratching caused by incorrect corking machineoperation

4) Example of still wine cork deformation

5) Example of over-insertion

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BOXE

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• Check the volume of theheadspace- The free volume between the base of the cork and thewine must be about 1% of thevolume of the wine at atemperature of 20°C [3], inorder to limit the increase ininternal pressure due to thedilation of the wine as aresult of an increase intemperature. For example, ina 0.75 l bottle, the volume ofthe headspace must be about8 ml. This volume can becalculated using the formulaV= π r2 h

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CROWN EFFECT(Excerpt from: “Manuale ditappatura per vini spumanti”) (4)

When the muselet is tied underthe bottle’s mouth, it causes anelastic deformation of thesection of cork stopper that isleft outside the bottle’s neckduring corking.This elastic deformationproduces the so-called crowncap effect. The crown cap effectis produced by metal crown capsthat are crimped onto the bottlemouth in such a way as tocompress a thin seal betweenthe metal part and the surface

of the bottle mouth.Muselets obtain the same effectby exploiting the flexibility anddeformability of a cork stopper,which is compressed axiallyonto the bottle mouth.The creation of this area ofmaximum compression of thematerial blocks the micro poresin the cork agglomerate byelastic deformation, soachieving the crown cap effect.

The picture illustrates the verticalcross-sections of two bottle necks,

the first closed with a crown cap andthe second with a crown cap effect

cork stopper with muselet. Thearrows indicate the contact areasbetween the crown cap effect cork

and the bottle.

03

Example of headspace height, equalto a free volume of 1% of the winevolume, in two types of 0.75 Bordeauxbottle

45 mm 45 mm

25 mm 27 mmø 20 mm ø 19 mm

- In practice, the height of the headspace is often used;however, this measurement isindicative and should beassessed according to thecharacteristics of the bottle

• Check that there are no vibrations andavoid sudden stops during corking

• Do not exceed the maximum number of bottles/hour percorking head recommended bymanufacturer (for still wines)

• Check that the cork shows nosigns of self-expulsion (formushroom shaped corking)

Muselet application (for sparklingand semi-sparkling wines):• Check muselet positioning and application

• Check that muselet does not affect cork orthogonality

• Check the length of the cork wire muselet after application(24 ± 1 mm). Thismeasurement refers to the0+2 cork; for other types (e.g.0+1) please refer to themanufacturer’s specifications.Make sure that the length iscorrect ensures a good sealas a result of the crown effect(see BOX E)

BOXF

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End of line checks

• Check the positioning of thecork at standard temperature(20°C)

• Check the liquid level atstandard temperature (20°C)

• Check that the overpressure inside the bottle is less than 0.5bar (for still wines)

• Check that there is no water ormoisture on the externalsurface of the cork beforecapsuling (for still wines)

• Check for damp corks beforepackaging in cartons

• Keep bottles upright at the endof the line for as long aspossible (minimum timerecommended: 3 hours) (seeBox F too)

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03BEHAVIOUR OF ONE-PIECECORK STOPPERS AFTERCOMPRESSION AND RELEASE

After compression by the corkingmachine jaws and release, one-piece cork stoppers have thefollowing dimensional recoveryrates:a) instantaneous: 85% of original diameter

b) after three hours: 95% of original diameter

c) after 24 hours: 99% of original diameter

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Temperature

The temperature of storage areasis a crucial variable in ensuringthe best possible seal betweencork and bottle and must be keptin the range 15 to 18°C. Rises intemperature cause the volume ofthe wine to increase (about 0.2ml/°C), reducing the headspaceand increasing the internalpressure. This puts the cork sealat risk.See Box G for further information

Suitability of the cellar

• Cork easily absorbs odours and cellar storage areas for bottlesmust be free of substanceswhich have a negative sensoryimpact, including halophenolsand haloanisoles

• Storage areas must be free of insects whose larva candamage cork (the most frequentare, for example, moths fromthe Tineidae and Oecophoridaefamilies)

• Current food and health regulations must be applied

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CELLAR STORAGEOF BOTTLED WINES

Example of insect damage to acork stopper. Also note signs ofwine leakage

BOXG

STOPPER/BOTTLESEAL SYSTEM (5, 6)

2

The leakage of wine from corkedbottles mainly affects one-piececork stoppers, but also othertypes, although less frequently.Although the phenomenon isgenerally referred to as leakage,there is a distinction between:• “leakage”, which is a more serious defect, with thepercolation of wine through thecork or along a crease; the lossof wine does not stop and ingeneral the bottle is unsaleable

• “Staining”, or the process by which wine leaks between theglass and the cork, causing aminimal loss of product; thestaining may be momentary

Apart from the appearance of thebottle, even a small seepage ofwine can increase the humidity onthe outer face of the cork or in thespace between the cork and thecapsule, which risks improvingfungal growth.

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Temperature

Wines bottled with straight corkmay have a risk of partial rising ofthe cork.For semi-sparkling wines,temperature rises cause anincrease in the internaloverpressure as indicated in theconversion table given in the tablealongside. This may cause a lossof internal overpressure.

2 4Bottle position during storage

In the past, the vertical orhorizontal storage of bottles ofstill wine was regarded as avariable able to control theingress of oxygen into bottles.Recent studies tend to minimisethe impact of the position ofbottles on the evolution of thewine they contain, as noquantitative differences betweenthe amount of oxygen to enter inthe two cases have been found [7].So far as concerns the effect onthe elasticity of the cork (with thepossibility of wine staining) and onthe increased risk ofcontamination through wine/corkcontact, the choice of bottleposition must take account of thecorrelation between internal neckprofile and cork stopperdimensions, type of stopper usedand style of wine.

Example of leakage andconsequent growth of mould on asparkling wine cork

Humidity

If the air is too dry, it can causethe outer surface of the cork todry out excessively, causing a lossof elasticity and seal problems.In overly damp environments, onthe other hand, mould canproliferate on the outer surface ofthe cork, accompanied by the riskof transmitting unpleasantflavours to the wine.The relative humidity must bebetween 60% and 80%.

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Tabella: Ratio between theoverpressure (expressed inPascal) of a semi-sparklingwine at 20°C and theoverpressure at a temperature t

041,851,801,741,681,641,591,541,451,681,641,361,321,281,241,201,161,131,091,061,031,000,970,950,930,910,88

012345678910111213141516171819202122232425

°C

Example of wineseepage on the outer

surface of a cork

Example of mouldproliferation on the

outer surface of a cork

Conservation of bottles after saleand consumption

The factors to take intoconsideration for the purposes ofpreserving the characteristics ofthe product are:• storage time before consumption• storage conditions (high temperature environments)

• consumption temperature(for sparkling wines)

• stopper freezing• correct corkscrew use• cleanliness of glasses

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Storage of bottles before sale

The distributor/retailer’s storagearea for bottles before saleshould have the followingcharacteristics:• no anomalous odours or substances that cancontaminate the product from asensory point of view

• controlled temperature(15-18°C) and humidity(60-80%); the bottles mustnever be subjected totemperatures over 40°C ortemperature swings of morethan 30°C

• ambient conditions must be such as to guarantee uniformconservation of the batch

Bottle shipment

During shipment, the quality ofcorking can be ensured if:• the containers and trucks used are in a good sanitary state andhave not been contaminated byprevious loads

• the bottles of wine have not been subjected to temperaturesover 40°C

• the bottles of wine have not been subjected to temperatureswings of more than 30°C

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SHIPMENT, STORAGEBEFORE AND AFTERSALE, CONSUMPTION

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1 2 3CHECKS/PRECAUTIONS

- check that there are no critical defects

- assess in advance the apparent relative density, state of agglomeration and torsion test of the body

- check in advance cork dimensions

- use suitable corkscrews and/or correct manual uncorking technique

- assess in advance the apparent relative density andstate of agglomeration of the body

- determine in advance optimum cork dimensions basedon the internal diameter and profile of the bottle neck

- check in advance lubrication state by assessing extraction force

- check in advance the internal profile of the bottleneck and that there is no reverse tapering

- check jaw compression diameter

- check cork insertion speed

- check headspace volume

- check correct muselet positioning

- check bottle storage and/or shipment conditions



- determine in advance optimum cork dimensions basedon the internal diameter and profile of the bottle neck

- check in advance the internal profile of the bottle neck


BOX C

NUOVO DISCIPLINARE

NUOVO DISCIPLINARE

SECTION 5.3

REFERENCES

NUOVO DISCIPLINARE

SECTION 2.1

NUOVO DISCIPLINARE

SECTION 3.1/BOX D

SECTION 3.2

SECTION 3.3

SECTION 3.3

SECTION 3.3

SECTION 5/BOX G

BOX C

NUOVO DISCIPLINARE

SECTION 2.1

SECTION 3.1/BOX D

SECTION 3.2

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ISSUE ORIGINS

- anomalies in cork

- non-compliant agglomerated body

- insufficient lubrication

- unsuitable corkscrews and/or incorrect technique used for uncorking


- diameter insufficient in relation to the internal diameter and profile of the bottle neck

- excessive lubrication

- internal neck profile non-compliant or unfit for use

- high overpressure:

n poor corking machine jaw compression

n cork inserted too slowly

n insufficient headspace volume

n incorrect muselet application

- temperature rise during bottle storage and/or shipment

- anomalies in disc cork

- diameter larger than the acceptable tolerance abovethe nominal value

- diameter unsuitable in relation to the internal diameter and profile of the bottle neck


- excessive cork stopper compression

CAUSES

CORK

CONSUMPTION

CORK

BOTTLE

CORKING

STORAGE

CORK

BOTTLE

CORKING

TROUBLESHOOTINGGUIDE06

Important information for the correctuse of this troubleshooting guide: • the table below lists causes, checks and precautions relatingto problems affecting bottledwine resulting from the cork,bottle, filling, capping, storageor consumption

• also indicated are various problems affecting bottledwine, the causes of which may be different from thosementioned above. Only the most frequent problems arepresented in this table, the causes of which relate toproduction steps prior to the wine coming into contactwith the cork. Other issues relating to good winemakingpractice are outside the scope of this manual

• cork stoppers for sparkling wine are intended as type 0+2

• the "references" column indicates where further information can be found in the Manual

• for analytical methods of checking cork stoppers consult "Nuovo disciplinare sulle metodiche analiticheper il controllo del tappo di sughero ad uso enologico" [2]

• checks and precautions are only indicated if they can be performed by users

1 STILL WINE2 SEMI-SPARKLING WINE3 SPARKLING WINE

CORK BREAKAGE

CORK PUSHEDABOVE BOTTLENECKLINE

DISC BREAKAGE

l

l l

l l l

l l l

l l

l l

l l l

l l l

l l l

l l l

l l l

l l

l l

l l l

l l l

l l l

l l l

l l l

41

1 2 3CHECKS/PRECAUTIONS


- determine in advance optimum cork dimensions based on the internal diameter and profile of the bottle neck

- perform in advance a boiling resistance test



REFERENCES

NUOVO DISCIPLINARE

SECTION 2.1

NUOVO DISCIPLINARE

SECTION 3.1/BOX D

SECTION 3.2

06

40

ISSUE ORIGINS

DISC DETACHMENT - diameter larger than the acceptable tolerance abovethe nominal value

- diameter unsuitable in relation to the internal diameter and profile of the bottle neck

- poor disc/body adhesion


- excessive cork stopper compression

- diameter smaller than the acceptable tolerance below the nominal value


- anomalies in cork

- inadequate surface coating treatments

- uncorrect cork stopper conservation


- moisture present on neck between cork and glass

- scratching, folding or flaring present

- cork skewed

- excessive cork compression

- poor cork stopper insertion

- incorrect muselet positioning

- high overpressure:

n poor corking machine jaw compression

n cork inserted too slowly

n insufficient headspace volume

- incomplete stopper dimensional recovery: insufficient vertical storage of bottles

- bottles stored in an environment that is too dry

- temperature rise during bottle storage and/or shipment

CAUSES

CORK

BOTTLE

CORKING


EXCESSIVE ABSORBTION /LEAKAGE / SEEPAGE

CORK

BOTTLE

FILLING

CORKING

STORAGE

l l

ll l

ll l

ll l

ll l

ll l




- perform liquid seal capacity

- check length and conditions of cork stopper storage


- check filling process

- check correct corking machine jaw operation

- check correct bottle position with respect to insertion punch


- check that cork is inserted 24 ± 1 mm after museletapplication



- check cork insertion speed

- check headspace volume

- wait at least three hours before laying bottles down

- check that storage area humidity is between 60% and 80%


l l l

l l

l l

l l l

l l l

l l l

l l l

l l l

l l

l

l l l

l l l

l l l

l l l

l l l

l l

l l

NUOVO DISCIPLINARE

SECTION 2.1

BOX C

NUOVO DISCIPLINARE

SECTION 2.3

SECTION 3.1/BOX D

SECTION 3.3

SECTION 3.2

SECTION 3.3

SECTION 3.2

SECTION 3.3

SECTION 3.3

SECTION 3.2

SECTION 3.3

SECTION 3.3

SECTION 3.4

SECTION 4.3

SECTION 5

43

1 2 3l l- check that there are no critical defects

- check that cork is inserted 24 ± 1 mm after muselet application


- check wine pressure in bottle

- check bottle conservation and/or shipment conditions

- see "loss of internal overpressure" section

BOX C

SECTION 3.3

SECTION 3.1

SECTION 3.3

SECTION 5

06

42

HARDWOOD CORK

HARD TO UNCORK

- anomalies in disc cork

- insufficient cork insertion

- internal neck profile cylindrical (virtually no taper)

- wine pressure too high

- high pressure due to incorrect bottle shipmentand/or storage

- bottles stored for very long periods

- fall in internal overpressure

CORK

CORKING

BOTTLE

WINE

STORAGE

SUNDRY

CORK

BOTTLE

CORKING

STORAGE

l

l l

l

l l


CHECKS/PRECAUTIONS REFERENCESISSUE ORIGINS CAUSES

l

- density too high

- diameter larger than the acceptable tolerance abovethe nominal value

- diameter too large in relation to the internal diameter and profile of the bottle neck

- bad choice of lubricant or insufficient amount used

- internal neck profile non-compliant (e.g. mouth withoverhang) or unfit for use

- anti-scratch coatings inside neck

- over-insertion of cork stopper

- unsuitable wine pressure

- wine pasteurised in bottle or bottled with an hot filling machine

- unsuitable cork stopper conservation

- check in advance the apparent relative density of the cork





- check in advance for widespread defects using bottling test

- check that cork is inserted no more than 24 ± 1 mmafter muselet application

- check wine pressure on corking; if it is correct, theremay be a subsequent loss of pressure (see "loss ofinternal overpressure")

- inform the cork supplier about the bottle treatment process

- check cork conservation conditions and period

NUOVO DISCIPLINARE

NUOVO DISCIPLINARE

SECTION 2.1

NUOVO DISCIPLINARE

SECTION 3.1/BOX D

SECTION 3.3

SECTION 3.3

SECTION 2.3

l l l

l l l

l l l

l l l

l l l

l l l

l l

l l

l l l

l l l

45

1 2 3




- assess in advance the release of oxidising substances




- check filling process

- check correct position of bottle with respect to insertion punch


- do not use grapes in bad sanitary state

- clean containers and equipment that come into contact with wine using chlorine-free products

- check in advance for the presence of contaminants

- store wine in areas free of contaminating substances

- store corks in a suitable area and do not leave in open sacks or hoppers


06

44

IRREGULAREVOLUTION OF WINE

- loss of cork seal:

n anomalies in cork

n diameter smaller than the acceptable tolerance below the nominal value

n diameter insufficient in relation to the internal diameter and profile of the bottle neck

n oxidising substance residues on cork


n internal neck profile non-compliant or unfit for use


n scratching, folding or flaring present

n poor cork stopper insertion

n moisture present on neck between cork and glass

n cork skewed

n incorrect muselet application

- contamination by grapes in bad sanitary state

- contact with containers or equipment that are not sufficiently clean

- contact with contaminated wood

- contamination of cellar environment

- unsuitable cork stopper usage and conservation

- temperature rise during storage and/or shipment ofbottles



CORK

BOTTLE

CORKING

WINE

STORAGE

l

l lBOX C

NUOVO DISCIPLINARE

SECTION 2.1

NUOVO DISCIPLINARE

SECTION 3.1/BOX D

SECTION 3.2

SECTION 3.3

SECTION 3.3

SECTION 3.3

SECTION 3.3

SECTION 2.3

SECTION 5

l

l l

l l l

l l l

l l l

l l l

l l l

l l

l l l

l l

l l l

l l l

l l l

l l l

l l l

l l l

47

1 2 3l l- assess in advance the relative density and state of

agglomeration of the body





- check correct position of bottle with respect to insertion punch



- check that the outer surface of the cork is dry and without fungal growth before capsule application

- check that on corking the outer surface of the cork is dry and without fungal growth

- check that storage area humidity is between 60% and 80%


- check in advance for determination of dust

- adequately clean the entire corking system before and during operation

- check correct corking machine jaw operation and the feed system

- check correct bottle position with respect to insertion punch

NUOVO DISCIPLINARE

NUOVO DISCIPLINARE

SECTION 2.1

CAPITOLO 3.1/BOX D

SECTION 3.2

SECTION 3.3

SECTION 3.3

SECTION 3.3

SECTION 3.3

SECTION 3.3

SECTION 4.3

BOX C

NUOVO DISCIPLINARE

SECTION 3.2

SECTION 3.2

SECTION 3.3

06

46

LOSS OF INTERNALOVERPRESSURE

MOULD GROWTHON OUTERSURFACE OF CORK

PRESENCE OFCORK DUST ORFRAGMENTS INWINE


- diameter smaller than the acceptable tolerance below the nominal value



- scratching, folding or flaring present

- cork skewed

- cork inserted too far

- incorrect muselet positioning

- moisture or liquids present on the outer surface of cork before capsule application

- moisture or wine present on outer surface of cork before corking

- bottles stored in overly damp environment

- anomalies in cork

- residual processing dust present

- corking machine not sufficiently clean

- cork damaged by corking machine jaws or feed system

- flaring and/or chipping with cork fragmentation due to bad centering

CORK

BOTTLE

CORKING

CORKING

STORAGE

CORK

CORKING

l l

l l

l l

l l l

l l l

l l l

l l l

l l l



l l l

l l

l l

l l

l l

l l

l l

49

1 2 3- check in advance lubrication state by assessing extraction force



- check wine pressure on corking


- sensory and/or instrumental analysis on corks

- sensory and/or instrumenal analysis on corks

- do not use grapes in bad sanitary conditions

- clean containers and equipment that come into contact with wine using chlorine-free products

- check in advance for the presence of contaminants

- store wine in areas free of contaminating substances

- store corks in a suitable area and do not leave in open bags or hoppers

- check bottle storage conditions

06

48

SELF-EXPULSIONOF CORK

SENSORY TAINTINGDUE TOCONTAMINATION BYMICROBIALMETABOLITES

- incorrect choice of lubricant or excessive amount used


- poor cork stopper insertion

- high wine pressure

- temperature rise during storage and/or shipment ofbottles

- contamination of cork in forest environment

- contamination of cork during processing

- contamination by grapes in bad sanitary conditions

- contact with containers or equipment that are notsufficiently clean

- contact with contaminated wood

- contamination of cellar environment

- unsuitable cork stopper usage and conservation

- unsuitable bottle storage

CORK

BOTTLE

CORKING

STORAGE

CORK

WINE

STORAGE

l l l



NUOVO DISCIPLINARE

SECTION 3.1/BOX D

SECTION 3.3

SECTION 3.3

SECTION 5

NUOVO DISCIPLINARE

NUOVO DISCIPLINARE

SECTION 2.3

SECTION 5

l l

l l

l l

l

l

l l

l

l l

ll l

ll l

ll l

ll l

ll l

ll l

51

1 2 3l l l- check in advance the apparent relative density of the

cork


- determine in advance optimum cork dimensions based on the internal diameter and profile of thebottle neck



- check that cork is inserted 24 ± 1 mm after muselet application

- check the position of the insertion punch and the muselet

- check wine pressure on corking

NUOVO DISCIPLINARE

NUOVO DISCIPLINARE

SECTION 2.1

NUOVO DISCIPLINARE

SECTION 3.1/BOX D

SECTION 3.3

SECTION 3.3

SECTION 3.3

06

50

TOO EASY TOUNCORK / CORKSPINNING INSIDETHE BOTTLENECK

- poor density

- diameter smaller than the acceptable tolerancebelow the nominal value

- diameter insufficient in relation to the internal

- bad choice of lubricant or excessive amount used


- insufficient cork insertion

- structural damage to cork

- high wine pressure

CORK

BOTTLE

CORKING


l l l

l l l

l l l

l l l

l l

l l l

l l


5352

1) H. Pereira, 2007. Cork. Biology, Production and Uses, Elsevier Ed., Amsterdam.

2) Nuovo disciplinare sulle metodiche analitiche per il controllo del tappodi sughero per uso enologico, 2011. [can be downloaded from thewww.federlegnoarredo.it website (“cork” section)]

3) Disciplinare sulla produzione ed utilizzo del tappo di sughero in enologia, 1996. Stazione Sperimentale del Sughero - Tempio Pausania,Istituto di Enologia - Università Cattolica del Sacro Cuore - Piacenza.

4) V. Mazzoleni, M. Addis, A. Bianco, A. Ferrero, 2008. Manuale di tappaturaper vini spumanti, www.unicatt.it/manualetappi.

5) M. Lambri, E. Grillo, 2006. I problemi di colatura della tappatura delle bottiglie di vino in relazione all’impiego del tappo in sughero,www.infowine.com - Internet Journal of Viticulture and Enology, no. 4/1.

6) J.M. Riboulet. C. Alegoet, 1986. Aspects pratiques du bouchage des vins, Bourgogne Publ., La Chapelle de Guinchay.

7) P. Lopes, C. Saucier, P.L. Teissedre, Y. Glories, 2006. Impact of StoragePosition on Oxygen Ingress through Different Closures into WineBottles, J. Agric. Food Chem., 54, 6741-46.

8) Charte des bouchonniers liègeurs, Cinquième édition, November 2006.

9) O. Colagrande, 1996. Il tappo di sughero, Chiriotti Ed., Pinerolo.

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cork technical manual for the correct use of cork stoppers · Assoenologi Stefano Zaninotto Amorim...

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Transcript of cork technical manual for the correct use of cork stoppers · Assoenologi Stefano Zaninotto Amorim...