red wine chem nemc
TRANSCRIPT
![Page 1: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/1.jpg)
The Chemistry of Red Wine:
pH, SO2 and Phenolics
Al Verstuyft, Ph.D.
Al Verstuyft Consulting LLC
Fickle Fermenters Wine Club
![Page 2: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/2.jpg)
![Page 3: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/3.jpg)
What is wine ??????? “...bottled poetry.” Robert Louis Stevenson
“Liquid Music...”
“It puckers your mouth.” –Art Buchwald “the beverage of moderation”
The blood of Christ A fate worse than death!
Susan B. Anthony
Sunshine held together by water -Galileo
The most gentle and
efficaceous of medicines “Wisdom and wit to the wise” -Archimedes
“Wine is proof that God loves us and desires us to be happy.”
Benjamin Franklin
An expression of place
![Page 4: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/4.jpg)
![Page 5: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/5.jpg)
![Page 6: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/6.jpg)
Maceration
![Page 7: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/7.jpg)
receiving
tank
How red wine is made
complete
(“dry”)
malolactic
fermentation
complete
(“dry”)
malolactic
fermentation
Elevage 6 -24
months
oak flavor extraction,
marriage & integration
mature
wines
fresh
wines
new wine
light,
simple
rich or
heavy
![Page 8: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/8.jpg)
![Page 9: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/9.jpg)
Mosel Cabernet
Riesling Sauvignon
fresh mature
pure sexy
focused fruit integrated voice
beautiful profound
crisp round
loves sunlight loves firelight
![Page 10: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/10.jpg)
Sensible pH “Zones”
3.1 pH
Fresh wine styles
low tannin arrested ageing crisp acid taste
mature wine styles
high tannin guided maturity soft acid taste
![Page 11: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/11.jpg)
![Page 12: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/12.jpg)
![Page 13: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/13.jpg)
![Page 14: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/14.jpg)
Why do some big red wines fail to age?
• Oxidized flavors (poor reductive strength)
– Vinegar (nail polish, sour finish)
– Aldehyde: sherry, nutty, lacking freshness
– Caramel, pruney, baked, dull
• Over-polymerized tannins (poor structure)
– Dry, grainy, dirty mouthfeel
– Precipitation of structure
– Aromatic disintegration unbalances flavors
![Page 15: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/15.jpg)
Phenolic:
Any compound containing a benzene ring
which carries an -OH.
0H
![Page 16: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/16.jpg)
The stability of anthocyanidins is dependant on pH. At a low pH (acidic conditions), colored anthocyanidins are present, whereas at a higher pH (basic conditions) the colorless chalcones forms are present.
![Page 17: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/17.jpg)
Flavonoid:
Any of the class of three-ringed phenolics
extractable from skins
A C
B
![Page 18: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/18.jpg)
Anthocyanin:
Any of the five red-colored
flavonoid monomers
A C
B
Malvadin, Delphinidin, Peonidin,
![Page 19: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/19.jpg)
Flavilium ion:
Low pH red-colored form
of an anthocyanin
A C
B
15 – 30% visible
at wine pH
![Page 20: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/20.jpg)
Anthocyanin monomers:
Subject to
bisulfite bleaching
A C
B
HSO3-
![Page 21: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/21.jpg)
Good Stuff about monomeric anthocyanins:
• Reactive: capable of improving structure
Bad Stuff:
• Nearly insoluble in 13% alcohol
• Colored only at low pH: 15-30% visible in wine
• Bleachable by SO2
• Vulnerable to attack by enzymes
• Vulnerable to oxidation
![Page 22: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/22.jpg)
Monomer:
A discrete small molecule which can serve
as a building block for a macromolecule
A C
B
A C
B
C4 – C8
![Page 23: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/23.jpg)
Polymer:
A C
B
A C
B
A C
B
A macromolecule created by
linking monomers together.
![Page 24: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/24.jpg)
Tannin:
A C
B
A C
B
A C
B
A polyphenol
with affinity for protein.
![Page 25: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/25.jpg)
+ 02 + H202
0 0H 0 0H
Interpretation of principle of
oxydation of di-phenols Singleton , 1987
![Page 26: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/26.jpg)
Example of polymerative regeneration (Singleton, 1986)
![Page 27: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/27.jpg)
Anthocyanin
(color)
Contains no
vicinal diphenol
(terminates
polymer)
Flavanol
(tannin)
Contains a
vicinal diphenol
(can oxidatively
polymerize)
Building Blocks of Red Wine Structure
![Page 28: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/28.jpg)
A C
B
A C
B
A C
B
A C
B
Polymeric Pigment:
Stable, unbleachable color which
is the basis of refined texture.
![Page 29: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/29.jpg)
The Importance of Color
• Wine appearance itself
• Key indicator of ripeness
• Declines during ripening
• Polymerization chemistry:
pigment is critical to wine texture
![Page 30: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/30.jpg)
Acknowledgements
Clark Smith, WineSmith
Mike Riddle, Fickle Fermenters
Tom Webber, Seguin-Moreau Copperage
George Shanks, Peripolli
U California Davis, Viticulture & Enology Dept.
Napa Valley Community College, V&E Dept.
![Page 31: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/31.jpg)
Q&A
or
Shall We Get a Glass of Wine?
![Page 32: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/32.jpg)
Reading List Technical Concepts in Wine Chemistry, Y. Margalit (1997);
Concepts in Wine Technology, Y. Margalit (200X)
Wine Analysis and Production, B.W. Zoecklin et.al.(1999);
Introduction to Wine Laboratory Practices and Procedures,
J.L. Jacobson (2010).
Wine Science: Principles and Application, R. Jackson (2007) 3rd ed.
Principles and Practices of Winemaking, R.B. Boulton et.al.(1999)
Handbook of Enology, Vol 1(2000a) & 2(2000b), Ribereau et.al
The University Wine Course, M. Baldy (1997)
Encyclopedia The Sotheby’s Wine Encyclopedia , Tim Stevenson (2007)
General An Ideal Wine, David Darlington (2011)
The Judgement, George Taber (2011)
![Page 33: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/33.jpg)
Articles Cited
1. “Vintage Chemistry” S.L. Rovner, C&EN p.30-32 May 1, 2006
2. “The Chemistry of a 90+ Wine” D. Darlington, N.Y. Times p. 36-
39, August 7, 2005
3. “Wine Sniffers Are Inconsistent” K.M. Reese, C&EN p. 44
December 3, 2001
![Page 34: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/34.jpg)
Maximum micro-oxygenation dose in clear red wine
0
1
2
3
4
5
43 45 46 48 50 52 54 55 57 59 61 63 64 66 68 70 72
T° F
ml/
l/m
oTEMPERATURE
as a major limiting factor
Maximum micro-oxygenation dose in clear wine
![Page 35: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/35.jpg)
![Page 36: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/36.jpg)
Poor anthocyanins lead to long, dry polymers
Color Dryness Softness
salivary protein
![Page 37: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/37.jpg)
High anthocyanins lead to short, soft polymers
Color Softness Longevity Dryness
![Page 38: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/38.jpg)
Flavilium Anthocyanin
520 nm
when protonated
(low pH)
![Page 39: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/39.jpg)
Boulton-modified Somers
• Good measure of visible flavilium at wine pH
• Poor anthocyanin molar estimator
Adams BSA precipitation / FeCl complexing
• Total phenol determination at A510
• Discriminates protein-precipitable polymer
• Good anthocyanin molar estimator
![Page 40: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/40.jpg)
Malvidin-3 Glucoside Ionization
0
10
20
30
40
50
60
70
80
90
100
pH
% f
lav
iliu
m
Dilute Aqueous
13% EtOH
2.0 3.0 4.0 5.0
Molar error at pH 3.6
can exceed 50%
![Page 41: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/41.jpg)
Adams method for molar estimation
of ionizable anthocyanin
-20
0
20
40
60
80
100
pH
A 52
0
Malvidin
Delphinidin
2.0 3.0 4.0 5.0
FeCl A510 luminescence
at pH 4.9 replaces
Folin-Ciaocalteu
Baseline
polymer
subtracted
Increase at
pH shift =
flavilium
![Page 42: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/42.jpg)
Maturity criteria
for optimum wine quality
• Berry inspection and tasting
• Skin anthocyanins (A520)
• Co-factor potential (A280 and A365)
• Browning from rot or oxidation (A420)
![Page 43: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/43.jpg)
Anthocyanin
(color)
Apolar rings
(Sparingly soluble)
Positively
Charged
(repel each other,
so cannot stack)
Tannins
Uncharged
(can stack
between anthocyanins
to create colloids)
Co-Pigmentation during Red Wine Fermentation
Flavanols
(A280)
& Super-Cofactor Flavonols
(A280 & A365)
120o bond angle
A365
![Page 44: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/44.jpg)
420 nm
Oxidative dimer cross-linkages:
correlates with browning,
i.e. general visible light
absorption by polyphenols
![Page 45: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/45.jpg)
Winegrape Phenolic Maturity (Northern Hemisphere)
“polymeric” pigment
(A520)
July August September October
bleachable anthocyanins
(A520) Flavonol super-cofactors (A365) ??
oxidative dimers (A420)
![Page 46: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/46.jpg)
Maturity criteria
for optimum wine quality
• Berry inspection and tasting
• Skin anthocyanins (A520)
• Browning potential (A280 and A365)
• Browning from rot or oxidation (A420)
• Hue = Browning from rot or oxidation (A420)
decline in A520
• Brix x berry weight detects sampling errors
![Page 47: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/47.jpg)
Viewing List
A Walk in the Clouds (1995)
– K. Reeves, A. Sanchez-Gijon, A. Quinn
Sideways (2004)
- P. Giamatti, T. Hayden Church, V. Madsen
A Good Year (2006)
– R. Crowe, M. Cotillard, A. Finney
Bottleshock (2008)
– C. Pine, A. Rickman, B. Pullman
![Page 48: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/48.jpg)
Listener’s
background
expectation of
musical genres
Performer Composer
Instrumental
Composition
MUSICAL APPRECIATION
STYLE
![Page 49: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/49.jpg)
Taster’s
background
expectation of
historical genres
Origin Winemaker
Varietal
Composition
WINE APPRECIATION
STYLE
![Page 51: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/51.jpg)
Madrona Vineyards
![Page 52: Red Wine Chem NEMC](https://reader030.vdocuments.us/reader030/viewer/2022021500/577ccd691a28ab9e788c49f3/html5/thumbnails/52.jpg)
Selected anthocyanidins and their substitutions
Anthocyanidin R3' R4' R5' R3 R5 R6 R7
Aurantinidin −H −OH −H −OH −OH −OH −OH
Cyanidin −OH −OH −H −OH −OH −H −OH
Delphinidin −OH −OH −OH −OH −OH −H −OH
Europinidin −OCH3 −OH −OH −OH −OCH3 −H −OH
Luteolinidin −OH −OH −H −H −OH −H −OH
Pelargonidin −H −OH −H −OH −OH −H −OH
Malvidin −OCH3 −OH −OCH3 −OH −OH −H −OH
Peonidin −OCH3 −OH −H −OH −OH −H −OH
Petunidin −OH −OH −OCH3 −OH −OH −H −OH
Rosinidin −OCH3 −OH −H −OH −OH −H −OCH3