christian e. butzke enology professor purdue university ...€¦ · •testing every wine stopper...
TRANSCRIPT
Christian E. BUTZKE
Enology Professor – Purdue University
President-Elect - ASEV
[email protected] 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
00
-08
-19
00
-08
-19
00
-08
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00
-08
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00
-08
-20
00
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00
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-20
00
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00
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00
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-08
-22
00
-08
-22
00
-08
-23
00
-08
-23
00
-08
-23
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
-08
-11
00
-08
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00
-08
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00
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00
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00
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00
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00
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00
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00
-08
-18
00
-08
-19
00
-08
-19
00
-08
-20
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 !