Christian E. BUTZKE

Enology Professor – Purdue University

President-Elect - ASEV

butzke@purdue.edu 1.765.494.6500 enology.butzke.com

Outline

Closure issues since 1994

Closure usage update

Closure quality improvements

Gas transport phenomena

The reduction problem

Bottling-related issues

Cork taint update

Advice

Wine Magazines & Cork Taint

“Cork Taint”

Cl

Cl

Cl

OCH3

TCA

= musty, moldy off-odor

2,4,6 Trichloroanisole

From Under The Cork Tree

Cork Taint

T’ain’t the bottle

T’ain’t the wine

Cork Stoppers

bark

new

bark

1934agglomerated

Twin-Top

molded

Cellukork

molded

SupremeCorq

extruded

Ecork

Cork Taint & Bottle Closures

• Sampling Procedures

• Case Study

• Taste Panel Evaluation

• Taste Panel Training

UC Davis CorkSensory QC Manual

Butzke & Suprenant

• Testing every wine stopper “economically impossible”

• Method based on testing “50 corks in 10,000”

• Testing method measures „releasable TCA„

• 50 corks are soaked for 24 h in white wine with 10% alc

• Chemical TCA analysis of the group soak as low as 1 ng/L

• Group soaks reflect the average gained by individual soak

Cork QC Manual: 7 years later

“Cork manufacturer has introduced

sophisticated QC procedures”

Advances in the Treatment of Granulate

Used to Make Agglomerated Corks

0 0

3543

17

2.5 2.5 00

10

20

30

40

50

60

70

80

PE

RC

EN

T O

F T

ES

TS

Less TCA Greater TCA

PE

RC

EN

TA

GE

O

F T

ES

TS

13

78

72 0 0 0 0

0

10

20

30

40

50

60

70

80

PE

RC

EN

T O

F T

ES

TS

Less TCA

PE

RC

EN

TA

GE

OF

TE

ST

S

Single shipment received 2006

Steam treatment

Single shipment received 2004

No steam treatment

Progress in Control of TCA in Natural Corks

as Shown by Bale Soak Scores Using SPME

18.4 15 16.4 15.7 11.5 15.97.1

-5

5

15

25

35

45

55

65

1

12/1999-12/2001

<1 ppt

1-1.5 ppt

1.6-2.0 ppt

2.1-2.5 ppt

2.6-3.0 ppt

3.1-4 ppt

4.1-5.5 ppt

80

11.95.8 2.1 0 0

0

20

40

60

80

1

04/2005-04/2006

>1 ppt

1-1.5 ppt

1.6-2 ppt

2.1-2.5 ppt

2.6-3 ppt

4.1-5.5

12/1999-12/2001

04/2005-04/2006

Closure Statistics

The PlumpJack Project 2000-2002

$200+ per bottle!

Corks and Bottle Aging

New 60 Years25 Years3 Years

Oxygen Permeability of Corks

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0.001 0.01 0.1 1 10

Permeability (CC O2 /Closure/Day)

Fra

cti

on o

f C

losu

res

(cum

ula

tive)

Synthetic Corks

Bark Corks

© Richard Gibson, Scorpex.net

Closure Testing - Mocon©

Ric

hard

Gib

son,

Scorp

ex.n

et

Oxygen Permeability of Corks

1000-fold variation in natural corks!

unpredictable “breathing” of wine

through the cork

RELATIVE TCA LEVELS FOUND IN DIFFERENT QUALITIES OF 45X24

CORKS FROM MULTIPLE DISCRETE CORK PRODUCES MONITORED

OVER A 6 MONTH PERIOD IN 2001

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0

PE

RC

EN

T

Less TCA ↔ More TCA

Conclusion: TCA is not related to visual quality. Please note, however,

that oxygen permeability is in a large part related to visual quality.

The Physics of Wine Bottle Closures

Professor Roger Boulton

Scott Chair in Enology and Chemical Engineering

Department of Viticulture and Enology

University of California, Davis

Presented at

ASEV Science of Closures Seminar

!

Bottle Storage

Permeation– Pressure driven

Diffusion– Concentration driven

Fick‟s Law

dn/dt = Deff[Ci –C0] / L

Henry‟s Law

KH = [C]i / Pi

Darcy‟s Law

dV/dt = k A [Pi-P0] / L / μ

2 Phenomena

Permeation– Pressure driven

Henry‟s Law

KH = [C]i / Pi

Darcy‟s Law

dV/dt = k A [Pi-P0] / L / μ

Diffusion– Concentration driven

Fick‟s Law

dn/dt = Deff[Ci –C0] / L

Permeation

– Due to Pressure Difference Pi – Po

– Headspace P exponential with Temperature

– Independent of Concentration Gradient

Diffusion

– Due to Concentration Difference [Ci] – [Co]

– Affected only weakly by Temperature

– Independent of Pressure Gradients

Permeation vs Diffusion

Darcy‟s Law

Permeation

k A ΔP

µ L

k Permeability

ΔP Pressure Difference

A Flow Area

L Depth of Medium

µ Viscosity

Fick‟s Law

Diffusion

- D (Ci – Co)

L

J Molecular Flux

D Molecular Diffusivity

Ci Inside Concentration

Co Outside Concentration

L Diffusion length

Permeation vs Diffusion

J = q =

Flow Through Porous Media

• Gas permeability of the cork

• Layers of alternative media

• Variability in porosity* from cork to cork

(*fraction of volume which is occupied by gas)

• Distribution of pore sizes

• Gas viscosity is 1/100th that of water

Important Factors:

Oxygen Radical Reactions

White

Red

O2 +

O2 +

Closure Evaluations

Oxygen Radical Reactions

≠ Diffusion Loss

Nota bene:

SO2 Loss: Natural Cork

SO2 Loss: Synthetic Cork

SO2 Loss: Screw Cap

The Reduction Problem

The Reduction Problem

The Reduction Problem

The Reduction Problem

Bottling Issues

Bottling

vs

Bottling Options

Just vacuum at filler+ Headspace sparging+ Vacuum at corker+ Bottle sparging w/N2

Bottling (under Nitrogen)

SO2 ManagementAccounting for Bottling Loss

pH and Molecular SO2

% SO2 molecular =

1 + 10pH - 1.83

100

Free SO2 = 0.85 • (1 + 10pH - 1.83)required

present

Giving Headspace

• SO2 Permeation = f(Headspace)!

• Headspace P exponential with Temperature

Effect of Headspace Volume on Bottle Pressure

5 C Rise and Fall, 750 mL

5.0

10.0

15.0

20.0

25.0

30.0

35.0

0 4 8 12 16 20 24

Time of Day (Hours)

Win

e T

emp

erat

ure

(C

)

0.70

0.90

1.10

1.30

1.50

1.70

Bo

ttle

Pre

ssu

re (

Atm

)

Bottle

Pressure

Wine

Temperature3 mLs

4 mLs

5 mLs

mLs

6 mLs

mLs

Effect of Headspace Volume on Bottle Pressure (and Permeation)

Wine

Temperature

Container Shipment - Pacific Wine Co.

217385 (shipped 8/18/00 - arrived 8/23/00)

60

70

80

90

100

110

120

00

-08

-18

00

-08

-18

00

-08

-18

00

-08

-19

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00

-08

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00

-08

-23

Wine ShippingHeat Exposure en Route

Tem

peratu

re (

°F)

Container Shipment-Glazer's Midwest

219945 (shipped 9/18 - arrived 9/21)

60

65

70

75

80

85

90

95

1000

0-0

8-0

7

00

-08

-08

00

-08

-08

00

-08

-09

00

-08

-10

00

-08

-10

00

-08

-11

00

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-11

00

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00

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00

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00

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-19

00

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00

-08

-20

00

-08

-21

Date

Temperature (°F)Daily Fluctuation

Shipment 215721

4 - 13°C To: New Orleans, LA

Advice

Don‟t give up on bark corks

Don‟t be afraid of alternatives

Don‟t confuse winemaking/closures

Adjust your SO2s @ bottling

Watch your fill height

Store your bottles sideways/upsdwn

Watch your wines‟ distribution

Don‟t forget to enter the

2009 Indy International !