1. PHENOLIC SECRETS: Time: 9:45am – 10:45am Moderator: Tinus Els
Exploring Finishing Tannins in Maturation and Blending
Time: 9:45am – 10:45am
Moderator: Tinus Els
Speakers:
Adolfo Alarcon – Winemaker / Technical Liason, Trinchero Family Wine Estates
Sabrina Lueck – Instructor of Enology, Walla Walla Community College
Richard Mansfield – North American Winemaker, Winery Exchange
Bernard Pradel – Co-Founder, Toasted Oak Co.

2. Finishing Tannins: Function, Fates, and Flavors Alternate Title: “Sabrina reads literature so you don’t have to!”
Sabrina Bitz Lueck
Walla Walla Community College / College Cellars

3. Today Difference between fermentation, ageing, and finishing tannins
Difference between hydrolysable and condensed tannins
Different hydrolysable tannin species
What do they do?
Different oak aroma species
Compare 4 finishing tannin products using ETS Laboratories data

4. Product Classes (Some Generalizations)
Fermentation Tannin
Ageing Tannin
Finishing Tannin
Tannin source
Can include grape, oak, chestnut, exotic wood,
gall nut
Mainly oak,
occasionally grape
Protein reactivity
Yes (laccase protection)
Yes
No (or low)
Antioxidant activity
Color stabilization
Some (maybe)

5. Grape Tannins: Non-Hydrolysable (Condensed) Tannins
Flavonoids (specifically procyanidins)
Origin
Grape seeds, skins, and stems
Non-toasted oak, chestnut or “exotic” woods, gall nuts
Function
Provides tannic structure
Monomers are bitter and astringent
Polymers are not bitter, but astringent
Anti-oxidant activity – reacts directly w/ O2
Maybe control expression of reduced sulfur aromas?
Quinone capture of volatile thiols
Fate
Buddying up with anthocyanins or other condensed tannins
Precipitation during extended ageing (oxidation involved)
Condensed tannin molecule (Scollary, 2010)

6. Oak Tannins: Hydrolysable Tannins
Non-flavonoid, ellagitannins and gallotannins
Origin
Toasted oak and gall nut
Gallic acid can also come from stems
Function
Sensory impact is controversial
Maybe synergistic impact
Doesn’t react well with salivary proteins
No “drying” mouthfeel?
Reacts pretty well with other stuff!
Fate
To hydrolyze (and react)
Ellagitannin → ellagic acid
Gallotannin → gallic acid
Vescalagin molecule (Waterhouse, 2002)

7. Function/Fate: Compound Capture
A few ellagitannins can capture grape or fermentation derived nucleophiles
Sulfur based – e.g. 3-sulfanylhaxan-1-ol “grapefruit / tropical”, methanethiol “rotten cabbage”
Anthocyanins – oenin forms anthocyano- ellagitannin, bathychromatic shift
+ H2O2
+ O2 → →
(Chatonnet et al., 1992)

8. Reduction to “Roasted”
Oak aromatic aldehydes can perform more than just aroma masking.
Furfural formed from oak wood hemicellulose degradation during toasting.
Chemical reaction occurs.
+ H2S →
Furfural
“sweet” “caramel-like” “toast”
Furfurylthiol
“roasted”

9. Things on the ETS Oak Phenolics Panel
Gallic acid – antioxidant, derived from gallotannins, little/no sensory effect
Ellagic acid – antioxidant, derived from ellagitannins, little/no sensory effect
Vescalin and castalin – derived from vescalagin and castalagin, react w/ nucleophiles (reduced sulfur and others)
Vescalagin and castalagin – reacts w/ nucleophiles (reduced sulfur and others)
Complex ellagitannins – other stuff, compounds that “read” as non condensed tannins, likely ellagitannins bound to other ellagitannins
Total ellagitannins – all the stuff!

10. Things on the ETS Oak Aroma Panel
Furfural + 5-methylfurfural – “butterscotch” “caramel”
cis-oak lactone + trans-oak lactone – “raw oak” “coconut”
Guaiacol + 4-methylguaiacol – “charred” “smoky” “spicy”
Eugenol + Isoeugenol – “clove”
Vanillin – “vanilla”

11. Oak Aromas: Lignin Derived Flavors
Guiacol “charred”
Eugenol “clove”
Lignin fills in spaces between other polysaccharides in cell walls. Provides mechanical strength.
Lignin fragment
4-methylguiacol
“smoky” “spicy”
Vanillin “vanilla”
(structures from Gavin Sacks, Cornell University)

12. Oak Aromas: Hemicellulose Derived Flavors
Hemicellulose is a long chain of sugar
Breakdown products taste/smell like cooked sugar
Furfural
“sweet” “caramel-like”
5-methylfurfural
“sweet” “caramel-like”
(structures from Gavin Sacks, Cornell University)

13. Let’s Look at Some Products
Oak Phenolics and Oak Aroma Compounds in 4 Products

17. Importance of a compound to the odor of a sample OAV = concentration / detection threshold
← Value = 17
Detection thresholds from Chatonnet 1995

18. Thank You

19. References
Chatonnet, P Influence des proceeds de tonnellerie et des techniques d’élevage sur la composition et la qualité des vins élevés en fûts de chêne. PhD Thesis. Université de Bordeaux, Bordeaux, FR. He, F., Liang, N., Mu, L., Pan, Q., Wang, J. Reeves, M., and C. Duan Anthocyanins and their variation in red wines I; monomeric anthocyanins and their color expression. Molecules. 17: He, F., Liang, N., Mu, L., Pan, Q., Wang, J. Reeves, M., and C. Duan Anthocyanins and their variation in red wines II; anthocyanin derived pigments and their color evolution. Molecules. 17: Kontoudakis, N Grape phenolic maturity; Determination methods and consequences on wine phenolic composition. Thesis, Rovira i Virgili University, Tarragona. Loch, R Micro-oxygenation: a large winery case study. In ASVO Proceedings of Seminar ‘Use of gases in winemaking’. Allen, M. (ed), pp Australian Society for Viticulture and Oenology. Adelaide. Ribéreau-Gayon, P., Glories, Y., Maujean, A., and D. Dubourdieu Handbook of Enology Volume 2; The Chemistry of Wine Stabilization and Treatments. John Wiley & Sons Ltd, Chichester, United Kingdom. Waterhouse, A Wine Phenolics. Ann. N.Y. Acad. Sci. 957:

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