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An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
CorkIndustryPerspective
CorkIndustryPerspective
Peter WeberCork Quality Council
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
Unintended Consequences
• Unforeseen variables increase with the length of time the control package has been used
• Magnitude increases with length of evaluation
Mag
nitu
de →
Number of Variables→
Calculating Unintended Consequences
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
Unintended ConsequencesElapsed Time - As Related to Closures
• Cork, as a sealing material, extends beyond ancient Greece.• It has been used in its current form with wine for over 300 years.• It has been the default closure component in the development of
traditional wine making practices.
Dom Perignon Agoston Haraszathy
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
Unintended ConsequencesVariables Evaluated - As Related to Closures
1. Off Aromas - TCA
2. Oxygen Permeability
3. Flavor Effects
4. Efficiency and Cost
5. Consumer Perceptions
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
Sources of TCA in Natural Corks
• Bioconversion of 2,4,6 Trichlorophenol (TCP) • Primarily by fungi
• Bioconversion through the production cycle has been virtually eliminated.
• Studies of forest samples show TCA present at levels between 1% and 3%
• Wood Near the Ground• Yellow Stain (Armillaria Mellea)
• Harvesting Protocols require the avoidance of wood with these characteristics
1 - Cork Closures and Off Aromas
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
TCA Reductions in Corks ReceivedCQC Members’ TCA Screening Results show an 82% Reduction in TCA over the Last Ten Years.
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
Q3-02 Q3-03 Q3-04 Q3-05 Q3-06 Q3-07 Q3-08 Q3-09 Q3-10 Q3-11 Q3-12
Ave
rag
e T
CA
(p
pt)
Sample Period
CQC Incoming TCA Analysis Average TCA(ppt) from Group Soaks of Natural Corks
TCA Reduction = 82%
• Currently test 30K Samples/year
• Graph includes over 200,000 data points.
• Last Quarter 90% of Samples were less than our MDL of 1ppt.
• Statistics record less than 1ppt as 0.5ppt.
1 - Cork Closures and Off Aromas
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
Cork Closures and Off Aromas
Screening for TCA with Group Cork Soaks
AVF/ETS Independent Study Demonstrates Effectiveness
Test# 1 2 3 4 5 6 7 8 9 10 AvgBale A <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 0.5Bale B 1.1 <1 <1 <1 <1 2.8 <1 <1 <1 <1 0.8Bale C <1 <1 4.2 <1 <1 <1 <1 <1 <1 2.0 1.0Bale D 1.4 1.3 1.8 1.7 1.9 1.2 5.2 1.3 2.1 1.7 2.0Bale E 1.9 2.0 2.4 2.8 2.9 2.0 2.2 2.7 2.8 4.1 2.6
Compare to what happened in 60 bottles after 20 months in wines bottled with corks from each of these bales
Replicates of 50-Cork Soak SPME Scores
1-2 ng/L 2-4 ng/L 4-8 ng/L > 8 ng/L % >2pptBottles from Bale A 0 0 0 0 0.0%Bottles from Bale B 0 0 0 0 0.0%Bottles from Bale C 1 0 0 0 0.0%Bottles from Bale D 3 0 1 0 1.7%Bottles from Bale E 3 2 1 0 5.0%
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
Cork Closures and Off Aromas
Screening for TCA with Group Cork Soaks
Same Results Evaluated by CQC Screening
Compare to what happened in 60 bottles after 20 months in wines bottled with corks from each of these bales
Replicates of 50-Cork Soak SPME Scores
Test# 1 2 3 4 5 6 7 8 9 10 AvgBale A <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 0.5 0 PassBale B 1.1 <1 <1 <1 <1 2.8 <1 <1 <1 <1 0.8 1 PassBale C <1 <1 4.2 <1 <1 <1 <1 <1 <1 2.0 1.0 2 ReTestBale D 1.4 1.3 1.8 1.7 1.9 1.2 5.2 1.3 2.1 1.7 2.0 6 FailBale E 1.9 2.0 2.4 2.8 2.9 2.0 2.2 2.7 2.8 4.1 2.6 10 Fail
CQC Flags
1-2 ng/L 2-4 ng/L 4-8 ng/L > 8 ng/L % >2pptBottles from Bale A 0 0 0 0 0.0%Bottles from Bale B 0 0 0 0 0.0%Bottles from Bale C 1 0 0 0 0.0%Bottles from Bale D 3 0 1 0 1.7%Bottles from Bale E 3 2 1 0 5.0%
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
So What is the Rate of TCA in Natural Corks?
Current CQC screening statistics • 94% below the minimum reporting level of 1ppt. • 5% are between 1-2%• 3% are rejected
Interpolating the AVF study of bottled wine at 20 months• translates to well under 1% taint
Observations - Christian Butzke • “TCA No Longer a Major Problem for the U.S. Wine
Industry” (Christian Butzke – 2011 - less than 1%)• Higher estimates often have broader definitions
1 - Cork Closures and Off Aromas
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
Methods Used to Measure Oxygen Ingress
• Mocon • Optical Density at 420 nm• Free SO2 / Total SO2
• Fluorescence Quenching• Colormetric
Indigo Carmine +Sodium Dithionite
Reduced…………..……………………….Oxidized
2 - Oxygen Permeability
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
2 - Oxygen Permeability
Colormetric Method (Bordeaux 2006)
Screwcap Natural Cork SyntheticsReduced Oxidized
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
2 - Oxygen Permeability
Variation between Corks
• Air volume in 44mm cork estimated at 3.4 to 3.6 mL• Compression during bottling is estimated to create
internal air pressure of 6-9 atm. • Sets up an environment for diffusion from high
pressure air in cork cells connected by Plasmodema (60 nm)
• Pressure is subject to variation in cork structure and bottling action
• Variances seen to expand over the first six months with gradual flattening after 12 months
• Indicates moderate ingress by diffusion, and does not show the steady ingress seen with permeability
Diffusion of Oxygen Due to Bottling ?
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
2 - Oxygen Permeability
Routes of Oxygen Ingress – for Two Closures
Lopes, P.; Saucier, C.; Teissedre, P.L., Glories, Y. Main routes of oxygen ingress through different closures into wine bottles. J. Agric. Food Chem. 2007,55, 5167-5170.
In this 24 month study - closures were tested with two levels of impermeable coverage…
1. Results for cork were similar under all scenarios indicating oxygen originating inside the cork with slight diffusion
2. Results are consistent with estimates of air displaced by cork compression during bottling
3. The uncovered Synthetic appeared to be permeable through the center of the closure body
Natural Cork Extruded Synthetic
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
2 - Oxygen Permeability
Wine is a Four Dimensional Product
In a survey of 100 wineries we asked respondents to estimate the average bottle age of their wine production before consumption• 17% >24 Months• 23% 12 -24 Months• 36% 3-12 Months• 24% 0-3 Months
0%
20%
40%
60%
80%
100%
1 3 6 9 12 18 24 36Estimated Months in Bottle Until Purchase
Estimated Bottle Ageby Winery Survey
17% + 24 Mos
23% 12-24 Mos.
36% 3-12 Mos.
24% 0-3 Mos.
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
2 - Oxygen Permeability
Summary of Findings• Tested Synthetics showed steady permeability• Natural Corks showed initial diffusion slowing at six
months and flattening after twelve months• Variation of OTR for Natural Corks range between
that seen for tested Synthetics and Screwcaps• Technical Corks had similar OTR performance to
that seen with Screwcaps• Screwcap with saran tin had the lowest level of
oxygen ingress• Both Synthetics and Screwcaps have developed
alternatives to improve performance.
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
3 - Flavor Effects
Comparisons need better consistency• Studies favoring cork include parameters of
“developed”, “buttery”, “balanced”, and “complex”• Studies favoring alternatives include parameters of
“fruit”, “fresh”, “lively”• Better integration with traditional evaluations
Attribute PtsAppearance 3Aroma/Bouquet 6Taste/Texture 6Aftertaste 3Overall Impression 2
20
American Wine SocietyAttribute Pts
Oxidised 1Glue-Like 1TCA 1Reduced 1Citrus 1Lime 1Pineapple 1Overall Fruit 1
AWRI Closure Study
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
3 - Flavor Effects
Reduction - Dimethyl SulfideIn a market study of Sauvignon Blancs, cork closures had significantly lower DMS levels than wines finished with screwcaps – by a ratio of 2.2 to 1
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
3 - Flavor Effects
Continued Flavor Research• DMS Example – mixed reviews at different
concentrations• REDOX properties effect more flavor components
than can be listed here• This is a great opportunity to study wine chemistry• But these flavor components are interconnected
and express themselves in a living wine over time• Can we control compounds that were developed in
the vineyard and fermentation tanks with targeted post bottling Oxygen permeation ?
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
4 - Efficiency and Cost
Opportunities and Challenges
• Higher Consistency = Less Adaptability• Glass Tolerances
• +/- 2.5mm for corks• Less for synthetics• +/- 0.25mm for threads
• Cost Difference• Alternatives and Technical Corks are
significantly less costly
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
4 - Efficiency and Cost
Technical Corks
1+1 Corks•Agglomerate very low in TCA•Disk Quality controls TCA transfer•Excellent Physical Consistency•Low Oxygen Ingress
Micro Agglo•Very low levels of TCA •Excellent Physical Consistency•Low Oxygen Ingress•Low Cost
Limited Suppliers
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
5 - Consumer Perceptions
Quality Considerations for the Consumer
11%
31%
93%
50%
16%
0%
0% 50% 100%
ScrewCaps
Synthetics
Natural Cork
Very High/High Moderate Somewhat Low/Very Low
Perception of Quality by Closure Type
• US Consumers have traditionally viewed cork closures to be associated with quality
• 2011 Updated Survey shows 93% of consumers perceiving High or Very High Quality
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
5 - Consumer Perceptions
Sustainable Attributes are a Consumer Plus
• Promoted by International Environmental Groups
• Supported by regional recycling programs
• Viewed a a model for sustainable industries
• Appeals to the natural attributes of the grape and vineyard
An Industry Perspective for Natural Cork WineFlavor 101 - Dec. 6, 2012
Prepared by the Cork Quality Council www.corkqc.com
Thank You