MW Geisenheim 0905

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ALTERNATIVE CLOSURESALTERNATIVE CLOSURES

-- A A TechnicalTechnical LookLook

Dr. Rainer JungGeisenheim Research InstituteDep. of Enology

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Worldwide 16 - 18 Billions Closures / year

Actually roughly:• 9 - 11 Billions Natural Cork• 5 - 7 Billions Technical Cork• 1,2 - 1,5 Billions Plastic stoppers• 1,2 - 1,5 Billions Screw caps

Natural Cork ca. 58 %

Technical Cork ca. 30 %

Plastic stoppers ca. 6 %

Screw caps ca. 6 %

QuelleQuelle: : GiovanettGiovanett , 2005, 2005

Bottle Closures for wine - diversity

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Cork – the natural product

CorkCork – the material with uniquephysical properties

CorkCork – the natural closure knownalso for problems in bottled wines

CorkCork – the traditionaland naturalclosure for wine

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Problems with cork stoppers:2 „Cork“ taint1 Leakage

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Natural Cork – Fakts

Corktaint – Percentage of wines with musty off-flavour

• 0,8 % Prüfstelle Rheinhessen/Alzey, 1994, 10941 wines• 0,2 – 2,9 % Prüfstelle Franken/Veitshöcheim, 1998-2000, 23559 wines• 0,7 % WSA-Study/England, 2001-2002, 13780 wines

0,7

0,9

0,6

1,1

0,3

0,7

0,2

%

Cork

Plastic

Others

mus

ty, mouldy

oxidat

ed

other off-flavours

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Cork - ProductsNatural cork stoppersSurface- and color-treated

„Technical“ corkstoppers, as an alternative

Quality ensurance

New treatments against taint problems

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Aluminium-Screw caps – the „traditionel“ alternative

• first only for simple wines,Image of mineral water

• diversity, relyability of the closures lead to a wide distribution

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Aluminium-Screw caps - Sealing

1 COMPOUND- PVC-Plastisol in Rotation - most material in the outer part

2 INSHELL MOULDING- liquid PE-Granuals, pressed into the form with a punch

3 SEALING DISCS- consist of different layers / materials- main structure: EPE (Expanded Polyethylen)- facing the wine with tin, Saran, Saranex

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Alternative stoppersDevelopment of plastic stoppers Different production techniques (injecting moulding, extrusion)

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TESTS WITH ALTERNATIVE CLOSURES AND CORK

2 Bottling and storage of wine(Bottling experiments, Tests after different storage-times and –conditions [temperature, bottle position] )

Several Testseries with alternative stoppers in Geisenheim since 1996

1 Mechanical Tests(Stucture, Specific weight, Elasticity)

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SPEZIFIC WEIGHT

0 0,1 0,2 0,3 0,4 0,5 0,6

[g/cm3]

Natural Cork

AgglomeratedCork

Plastic

12

100 200 300 400 500 600

[N/cm3]

Natural Cork

AgglomeratedCork

Plastic

ABSOLUTELY

2300-2800 N

4300-4800 N

2500-9800 N

COMPRESSIONFORCES IN CORKER

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“Cellular structure“ and porosity of plastic-stoppersproduced by injection mouldinginjection moulding

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“Cellular structure“ and porosity of plastic-stoppers produced by extrusionextrusion

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BOTTLING TRIALS(Variants / closure system)

Bottling of all closure systems under controlled and identical conditions

Storage of each 50% of bottles at 25 –35 °C & 15 °C

„WARM“ „COLD“

Storage of each25% of bottles horizontal & vertical horizontal & vertical

Analytical and sensory testing of wines after 6 month („warm“), 12 month(„warm & cold“), 24 month („cold“)

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Problems with plasticstoppers

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INNER BOTTLE PRESSURE(directly after Insertion of stoppers)

0 1 2 3 4 5

[bar]

Natural Cork

AgglomeratedCork

Plastic

Bottling of 800 Flaschen / h, n =12

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INNER BOTTLE PRESSURE(TIME STUDY, Measurement by „manometric pipettes“)

Inner bottles pressure during storage time(Plastic stopper)

0,0000,5001,0001,5002,0002,5003,0003,5004,0004,500

direc

t

after

10 m

in.

after

30 m

in.

after

1 h

after

3 h

after

6 h

day 2

, morn

.

day2

, afte

rn.

day 3

, morn

.

day 3

, afte

rn. day 4

day 5

day 6

day 7

day 8

day 9

day 1

0

day 1

1

day 1

2

day 1

3

day 1

4

Time

[ba

r]

vertical storage, without CO2 horizontal storage, without CO2 vertical storage, with CO2 horizontal storage, with CO2

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HUMIDITY OF DIFFERENT CLOSURES(after 8, 12 und 18 month storage horizontally/warm [25-30°C])

0

1

2

3

4

5

6

7

8

9

8 month 12 month 18 month

[%vo

l.]

Natural

Natural

Natural

Natural

Agglo big p.

Agglo fine p.

Twintop

Plastic

Plastic

Plastic

Plastic

Plastic

Plastic

Plastic

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FREE SO2 LEVELS(after 3, 6, 12, 24 and 36 month storage, “COLD“ [15°C])

10

15

20

25

30

35

40

45

3 6 12month

24 36

[mg/

L]

Cork vertical

Corkhorizontal

Plasticvertical

Plastichorizontal

Screw Capvertical

Screw Caphorizontal

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FREE SO2 LEVELS(after 3, 6, 12, 24 and 36 month storage, “WARM“ [25 - 35°C])

10

15

20

25

30

35

40

3 6 12month

24 36

[mg/

L]

Cork vertical

Corkhorizontal

Plasticvertical

Plastichorizontal

Screw capvertical

Screw caphorizontal

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Glass closure – Alcoa Vino-Lok - Development

• Idea: Imitation of a glass stopper known from Medicine and Pharmacy

• Development since 2002 Alcoa / Worms

• Early tests in wineries

• Tests in Geisenheim since Juli 2003

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Glass closure – Alcoa Vino-Lok - Sealing

ALCOAALCOA--„VINO„VINO--LOK“LOK“(„Glass(?) on Glass“)

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Glass closure – Alcoa Vino-Lok - Testing program

• 5 Closures - Natural Cork- Screw cap- Synthetic stopper- Vino Lok Glass (VLG)- Vino Lok Plexiglass (VLP)

• 4 Storage variants - vertical / horizontal- cold (15°C) / warm (25-30°C)

• 4 – 5 Test Intervals - 3, 6, 12, 24, perhaps. 36 months

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Glass closure – Alcoa Vino-Lok - SO2

ContentContent of of free free SOSO22 in in the wines during storagethe wines during storage(after 3, 6,12 and 24 months storage, COLD [15 °C], Means of n= 10))

30

35

40

45

50

55

60

65

Bottling 6 months 12 months 24 months

[mg/

L]

Cork vertical

CorkhorizontalPlasticverticalPlastichorizontalScrew capverticalScrew caphorizontalVLG vertical

VLGhorizontalVLP vertical

VLPhorizontal

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Glass closure – Alcoa Vino-Lok - SO2

ContentContent of of free free SOSO22 in in the wines during storagethe wines during storage(after 3, 6,12 and 24 months storage, WARM [25 – 30 °C], Means of n= 10))

30

35

40

45

50

55

60

65

Bottling 3months

6months

12months

24months

[mg

/L]

Cork vertical

CorkhorizontalPlasticverticalPlastichorizontalScrew capverticalScrew caphorizontalVLG vertical

VLGhorizontalVLP vertical

VLPhorizontal

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Glass closure – Alcoa Vino-Lok - Sensory

SENSORY, after 12 month storage

• Tasting in Geisenheim with 105 panelists and Oppenheim with 16 panelists

• Four Rankings each with 5 variants:1. warm / vertical, Cork, Synthetic, Screw cap, Glass, Plexiglass2. warm / horizontal, Cork, Synthetic, Screw cap, Glass, Plexiglass3. kühl / vertical, Cork, Synthetic, Screw cap, Glass, Plexiglass4. kühl / horizontal, Cork, Synthetic, Screw cap, Glass, Plexiglass

• Randomized Samples, Calculation with FIZZ

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SENSORY Results, after 12 month storage

• significant difference in two out of four rankings

• samples with Natural corkNatural cork in both series with significance on PlacePlace 1 1 (but also some bottles with cork-taint!)

• samples with Synthetic stopperSynthetic stopper in both series with significance on last last placeplace

- at warm / horizontal storage (**) Synthetic stopper significantly worse than all other closures

- at cold / vertical storage (*) Synthetic stopper significantly worse than natural cork stopper and screw cap and as well as vino-lok-variants

Glass closure – Alcoa Vino-Lok - Sensory

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Glass closure – Alcoa Vino-Lok - Questions

• Tests concerning the sealing over a longer storage period are atthe moment not available

• Automized solutions for packaging, putting the closure on the bottle,closing of the bottle are under construction

• Glass as a „sensitive“ material has to be handled with care,the head-line „Glass in wine“ would be fatal

• Price ? (ca. 30 - 40 €Cent, für Glass closure & Alucap, without printingand bottle)

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Bottle closures for wine

S U M M A R Y S U M M A R Y A N D A N D O U T L O O KO U T L O O K

?? Problems Problems withwith thethe naturalnatural product made theproduct made the ChancesChances forfor AlternativesAlternatives

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?? TaskTask of independent of independent institutesinstitutes::1. 1. CooperationCooperation withwith industryindustry forfor newnew--developpmentdeveloppment and and improvementimprovement2. 2. QualityQuality--assurance assurance and and improvement for established closuresimprovement for established closures3. 3. Publication Publication and and transfer transfer of of results results in in practisepractise

?? Problem: Problem: A lot of people A lot of people areare talkingtalking aboutabout bottlebottle closuresclosures forfor winewine!!OnlyOnly a a fewfew expertsexperts reallyreally knowknow something serioussomething serious!!