1. How do cultural practices impact wine aroma and flavor?
Nick Dokoozlian
E&J Gallo Winery

2. and wine flavor in the vineyard?
How do we manage grape
and wine flavor in the vineyard?
Outline
Measuring quality and flavor development
Practices influencing flavor development
Harvest date
Crop load
Late season water status
Trellis
Clonal selection
Summary

3. Measuring grape quality
Aroma
Taste
Color
Mouthfeel
Flavor = aroma x taste

4. How do we manage grape
and wine flavor in the vineyard?
Harvest
Date

5. Cabernet Sauvignon grapes at harvest in California
Mean soluble solids of
Cabernet Sauvignon grapes
at harvest in California

6. ?

7. Berry maturity metrics

8. Berry Sensory

9. Berry Sensory Berry sensory trends
Trained tasters can consistently distinguish several different flavor or aroma buckets during ripening
Significant sensory trends
are apparent during the later stages of ripening (>20 oBrix)

10. Sensory “flavor buckets” in grape berries near harvest
Responsible
compounds
Category
Negative
Veggie
Methoxypyrazine C6 compounds
Positive
Green fruit
Fresh fruit
Cooked or
jammy fruit
Glycosylated bound precursors, acid esters and thiols
Ex: norisoprenoids

11. ?

12. ?

13. ?
Sugar-based
harvest

14. ?
Sugar-based
harvest
Sensory-based
harvest

15. Berry to Wine Sensory

16. Linking berry and wine sensory
Berry sensory is subjective and not high- throughput
Can we use chemistry to describe our major aromas buckets?
Vegetable
Green fruit
Fresh fruit
Jammy fruit
Are chemical finger prints for each bucket possible ?

17. Grape aromas & aroma precursors
Methoxypyrazine
Veggie aroma
Free volatile aromas
Alcohols, aldehydes, terpenoids, norisoprenoids
Glucose glycosides
Flavor precursors bound to sugars
Fatty acid esters
Acid esters (fresh fruity notes in all cultivars)
Thiols
Sulfur based precursors in grapes ( ex. cysteine) - tropical notes in Sauvignon blanc, other cultivars

18. Sensory “flavor buckets” in grape berries near harvest
Responsible
compounds
Category
Negative
Veggie
Methoxypyrazine C6 compounds
Positive
Green fruit
Fresh fruit
Cooked or
jammy fruit
Glycosylated bound precursors, acid esters and thiols
Ex: norisoprenoids

19. Jammy fruit aromas Compound Aroma Benzyl alcohol (ppb)
Phenethyl alcohol (ppb)
Geraniol (ppb)
B-ionone (ppb)
Terpinene (ppb)
Linalool (ppb)
Eucalyptol (ppb)
B-damasecenone (ppb)
Red berry
Roses
Citric
Prune
Citrus
Flowery, lavender
Eucalyptus
Rose wood

20. The Odor Activity Value (OAV)
Concentration of target
compound in grape
Known sensory detection threshold in water
Example:
4000 ppt
OAV=
= 40
100 ppt

21. Cabernet Sauvignon Veggie
Chemistry
Aroma activity value

22. Cabernet Sauvignon
Green fruit
Aroma activity value

23. Cabernet Sauvignon Jammy fruit
Aroma activity value

24. Managing wine flavor & alcohol in the vineyard
How do we synchronize berry
sugar and flavor accumulation ?

25. Changes in berry sensory over time
2004
2004
Rapid sugar accumulation due to low crop load
Delayed flavor development due to environment, ripening rate

26. Changes in berry sensory over time
Slow sugar accumulation due to large crop load
2005

27. Crop Load or Vine Balance How do we manage grape
and wine flavor in the vineyard?
Crop Load or
Vine Balance

28. Yield to pruning weight ratio integrates vine capacity and yield
Crop Load
Yield to pruning weight ratio
integrates vine capacity and yield
Canopy size
Fruit yield
Accounts for differences in vineyard design,
plant density, vine vigor and site capacity

29. Vine balance and ripening rate Expected ripening rate
Vine yield
Pruning weight
Expected ripening rate
< 4
5 – 8
> 10
Too little crop = rapid
Balanced = optimum
Too much crop = slow

30. Cabernet Sauvignon Under-cropped vines Yield = 4 tons per hectare
Yield pruning weight ratio = 3
Over - cropped vines
Yield = 30 tons per hectare
Yield pruning weight ratio = 14
Balance - cropped vines
Yield = 15 tons per hectare
Yield pruning weight ratio = 8

31. Cabernet Sauvignon Under-cropped vines Yield = 4 tons per hectare
Yield pruning weight ratio = 3
Over - cropped vines
Yield = 30 tons per hectare
Yield pruning weight ratio = 14
Balance - cropped vines
Yield = 15 tons per hectare
Yield pruning weight ratio = 8

32. Balanced
Cropped = 8:1
Under
Cropped = 3:1
Over
Cropped = 14:1

33. Ratio of dark fruit to green aromas
Balanced-cropped
8:1 TT
Threshold
Under-cropped
3:1
Ratio of dark fruit to green aromas
Over-cropped
14:1

34. Under
cropped
Over
cropped

35. affect berry aroma at maturity ?
How does ripening rate
affect berry aroma at maturity ?
High LA:FW
(Under cropped)
How important is
D sugar
to:
time
Low LA:FA
(Over cropped)
Fruit aroma
accumulation?
Green aroma
degradation?
Sugar accumulation rate (oBrix)
Flavor accumulation
Rate?
Veraison
Harvest
Berry ripening (time)

36. Late Season Water Stress How do we manage grape
and wine flavor in the vineyard?
Late Season
Water Stress

37. Begin treatment at 21 Brix Ramp-up irrigation = 100% ETc
Control irrigation = 70% ETc
Ramp-up
Begin ramp-up
Control
Begin treatment
at 21 Brix

38. Vine response to irrigation levels during the final stages of ripening
Cabernet Sauvignon - Lodi
Treatment
Soluble solids at harvest (Brix)
Berry
Color
(mg/g)
IBMP
(ppt)
Bound
aroma precursors
Standard
26.7a
1.2 a
2.1 a
50,560 b
Ramp-up
24.5 b
1.1 a
1.4 a
59,860 a
From: Prichard et al 2005

39. Trellis Design and Canopy Efficiency
How do we manage grape
and wine flavor in the vineyard?
Trellis Design and Canopy Efficiency

40. 75% Exposed LA
45% Exposed LA
35% Exposed LA
65% Exposed LA

41. From Kliewer and Dokoozlian - 2000

42. Back to basics - performance metrics
Indices
Measure
Fruit yield
Production efficiency
Canopy efficiency
Fruit microclimate
Pruning weight
Exposed leaf area
Total leaf area
Exposed clusters
Total clusters

43. Clonal Selection How do we manage grape
and wine flavor in the vineyard?
Clonal Selection

44. Merlot Clones – 2009 Vintage
All clones adjusted to
similar crop loads (~7:1)
following berry set

45. Summary
Maturity measures are changing from sugar-based metrics to flavor-based metrics
Berry sensory and analytical tools can monitor berry flavor profiles
Vine balance (ratio of yield to pruning weight) is critical to fruit ripening rate and flavor development
Synchronizing sugar and flavor accumulation
Greater focus on the impact of other vineyard practices on flavor development is needed

46. Acknowledgements
David Vasquez, Luis Sanchez, Marin Mendez, Jim O’Donnell and Nona Ebisuda
Mike Cleary, Beth Wilson and Lee Raley
Laure David, Jim Kolsky and Lyndsay Noble
Cyd Yonker and Tom Pugh
Alan Reynolds and Jim Collins