1

ALTERNATIVE CLOSURESALTERNATIVE CLOSURES

-- A A TechnicalTechnical LookLook

Dr. Rainer JungGeisenheim Research InstituteDep. of Enology

2

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

3

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

4

Problems with cork stoppers:2 „Cork“ taint1 Leakage

5

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

6

Cork - ProductsNatural cork stoppersSurface- and color-treated

„Technical“ corkstoppers, as an alternative

Quality ensurance

New treatments against taint problems

7

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

8

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

9

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

10

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)

11

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

13

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

14

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

15

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“)

16

Problems with plasticstoppers

17

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

18

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

19

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

20

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

21

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

22

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

23

Glass closure – Alcoa Vino-Lok - Sealing

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

24

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

25

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

26

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

27

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

28

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

29

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)

30

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

?? NewerNewer Alternatives Alternatives have have to to prove their efficiencyprove their efficiency, , ShortShort-- and and middlemiddle time time studiesstudies areare notnot enoughenough

?? 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!!