The document summarizes a seminar on the production of spirits. It discusses the formation of flavor through grains, yeast, fermentation, distillation and maturation. It then covers vertical tastings of new and aged spirits and the science of aging in barrels. Finally, it discusses different oak species and their impact on flavor.

1. THE DNA OF FLAVOR
WORLD CLASS BARTENDER LAB

2. Seminar agenda
1. Welcome – Please Taste Responsibly
2. Formation of Flavor
a) Grains
b) Yeast
c) Fermentation
d) Distillation
e) Maturation
3. Vertical Tasting – New Spirit Through Mature Spirit
a) Sensory Analysis
b) E-Nose Data
4. The Science of Location – Rickhouse 101
5. Oak Species – American vs. European vs. Japanese
6. Q&A

3. Glossary
• E-NOSE. Mass spectrometry technology. Gives give fast, accurate data on aromas present in liquid / gas.
• CONGENER. A chemical constituent that gives a distinctive character or aroma. Some are valued in spirits whereas others are
removed.
• SACCHAROMYCES CERIVISIAE. Distiller’s yeast, this strain is used in all types of whisk(e)y.
• LACTOBACILLI. A bacteria that occurs in the fermentation process, which gives a creamy, fruity flavor and is found in beers and
whiskeys that employ long fermentations.
• ORTHONASAL OLFACTION. Inhaling aromas through the nose.
• RETRONASAL OLFACTION. Inhaling aromas over the palate / nasal cavity and out through the nose.
• QUERCUS ALBA. American white oak.
• QUERCUS ROBUR. European oak.
• QUERCUS MONGOLICA. Japanese white oak.
• ADSORPTION. The adhesion of molecules to a surface (copper / charcoal).
• BETA DAMASCONE. Belongs to a family called ‘rose ketones.’ Gives a floral, apple flavor.
• SYRINGOL (DIMETHOXYPHENOL). Produced by the thermal breakdown of lignin. Gives a smoky, peppery flavor / aroma.
• ISOBUTANOL (METHYL PROPONOL). Organic compound found in distilled spirits. Has a slight ‘damp’ aroma.
• DMS (DIMETHYL SULPHIDE). An ‘organosulphur’ that occurs during the production process. Gives unwanted flavors that are
removed by copper and charcoal by adsorption.
• LIGNIN. A complex organic polymer that makes up part of the structure of wood. When heat-treated, it releases aromatic aldehydes
like vanillin (vanilla flavor).
• HEMICELLULOSE. Complex polysaccharides (wood sugars) that, when heat-treated, leach out sweetness and form flavors like
maltol (butterscotch).
• PHENOLS. Aromatic organic compounds famous for giving Scotch its smoky flavor and aroma. Also found in wood and will give a
smoky note to un-peated whiskeys like bourbon.
• HETEROCYCLIC NITROGEN COMPOUNDS. Give a roasted, nutty character.
• VISCIMETRY. Visible physical reaction that occurs when liquids of different viscosity (e.g. ethanol, water) collide.

4. Your tasting mat

5. The e-nose

6. Quantitative-analytical progression
• E-nose detected 8 chemical compounds of significance
Compound Sensory Descriptor
1-propanol Alcoholic, fruity, pungent
Ethyl acetate Butter, caramelized, fruity orange, pineapple, sweet
2-methyl-1-propanol Alcoholic, leek, licorice, winey
n-Butanol Cheese / fermented, fruity, medicinal
3-methyl-1-butanol Balsamic / fermented, fruity, malty, ripe onion
Iso-amyl acetate Banana, fresh, pear, sweet
Ethyl-octanoate Anise, baked fruit, floral, green, waxy / sweet
Beta-damascenone Apple, apple rose, fruit, honey, sweet tobacco

7. Mash bills
• A mash bill is a pre-determined mixture of grains that are then ground and
cooked to extract fermentable sugars prior to fermentation
• Backbone of bourbon and usually
makes up the majority (70%+) of its
mash bill.
• Gives a very high yield of alcohol and
as a result is used extensively in both
the American and Scotch whisk(e)y
(for “grain whisky”).
• Lends a distinctive roundness /
sweetness to the final spirit.
• Indigenous grain crop to N. America
CORN RYE
• Another indigenous crop to N.
America that was used by the early
settlers to make bread and distill.
• Maryland and Pennsylvania were the
original heartland of rye.
• Requires more skill to produce and
gives far less yield than corn or
barley.
• Gives a spirit a distinctive spicy,
peppery character.

8. Mash bills
• One of the first “domesticated”
grains and has been used for making
food, predominately bread, since the
Neolithic period.
• Its use in bourbon was made famous
by brands that were initially
produced at Stitzel-Weller.
• Gives a sweetness and slight creamy
flavor to the spirit creating a “softer”
style of bourbon
• Used for two key reasons:
• Firstly, it delivers a large amount of
the enzymes that convert starches to
sugars, making it a very efficient
catalyst to ensure a good yield and
fermentation.
• Secondly, it adds depth of flavor
giving a malty and cereal character to
the spirit.
WHEAT BARLEY

9. Bourbon whiskey
• Three main bourbon mash bills are used in the industry:
1. ‘HIGH CORN’ BOURBON.
- The most common style available.
- Will have at least 70% corn, but can be as high as 100%.
- Sweeter on the palate.
2. ‘HIGH RYE’ BOURBON.
- The higher amounts of rye will counter the sweetness of the corn giving
a more spicy, peppery character.
3. ‘WHEATED’ BOURBON.
- Usually high in corn but with no or little rye, which will be replaced
with wheat
- Sweet, soft and creamy flavor.

10. Rye whiskey
• Rye whiskey was one of the first commercially distilled spirits in America.
The heartlands of Rye were Pennsylvania and Maryland.
• Post-Prohibition, the US government flooded the market with cheap aged
rye, effectively destroying the distillers who couldn’t compete on age or price.
• Rye is a difficult whiskey to produce for various reasons. It is very viscous
and can burn onto stills if the distiller isn’t careful. It can also be affected by
ferulic acid.
• Rye whiskey is known for its dry, spicy quality. The higher the rye
(minimum 51% of mash bill for American) the drier and more spicy the spirit.

11. Bulleit Frontier Whiskey
• What is the importance of a mash bill?
BULLEIT RYE
95% Rye
5% Malted Barley
BULLEIT BOURBON
68% Corn
28% Rye
4% Malted Barley

12. Yeast strains
Saccharomyces Cerevisiae

13. Yeast history
• Yeast research started in the late 1600s shortly after the invention of the
microscope
• It wasn’t until Louis Pasteur’s groundbreaking research in the late 1800s that it
was fully understood that yeast ‘metabolizes’ sugars to produce alcohol.
• There are many types of yeast used for different industries (beer, bread,
etc.), but the only one used in the distilling industry is
SACCHAROMYCES CERIVISIAE.
• Many distillers used to use wild yeast strains that they cultured and continue to
use today. They can have radically different effects on the final spirit. There
are fruity yeasts, spicy, nutty, etc. – and they all lend flavor to the new spirit
character and the final matured product.

14. Yeast strains

15. Fermentation
SHORT 20-30 HRS LONG 50+ HRS
NUTTY / SPICY CREAMY / FRUITY

16. Copper

17. Copper
Copper Pot Still
Photo Credit: Willet Distillery

18. Copper
George Dickel Beer Still
Photo Credit: Ewan Morgan

19. Killer graph – distillery characterTaste
Maturation
Distillery Character

20. New spirit tasting

21. E-nose data for sample 1 – Bulleit Rye new make
BULLEIT RYE – O M
BULLEIT RYE – 4 M
BULLEIT RYE – 25 M
BULLEIT RYE – 55 M
BULLEIT RYE – 134 M
BULLEIT RYE – FINAL
Ethyl acetate
Ethyl acetate
3-methyl-1-butanol3-methyl-1-butanol
Ethyl octanoate
Beta-damascenone
Beta-damascenone
Ethyl octanoate
2-methyl 1-propanol
2-methyl 1-propanol

22. E-nose data new make wheated Bourbon
22
Ethyl acetate
Ethyl acetate
3-methyl-1-butanol3-methyl-1-butanol
Ethyl octanoate
Beta-damascenone
Beta-damascenone
Ethyl octanoate
2-methyl 1-propanol
2-methyl 1-propanol

23. Quantitative-analytical progression
• E-nose detected 8 chemical compounds of significance
Compound Sensory Descriptor
1-propanol Alcoholic, fruity, pungent
Ethyl acetate Butter, caramelized, fruity orange, pineapple, sweet
2-methyl-1-propanol Alcoholic, leek, licorice, winey
n-Butanol Cheese / fermented, fruity, medicinal
3-methyl-1-butanol Balsamic / fermented, fruity, malty, ripe onion
Iso-amyl acetate Banana, fresh, pear, sweet
Ethyl-octanoate Anise, baked fruit, floral, green, waxy / sweet
Beta-damascenone Apple, apple rose, fruit, honey, sweet tobacco

24. Maturation science
CASK MECHANISM OUTCOME EXAMPLE
SUBTRACTIVE Removes immature
elements from new make
spirits
Sulphur compounds,
immature off notes
ADDITIVE Adds wood-derived
flavors from the cask
Vanillin, oak lactone
INTERACTIVE Converts spirit and
extractive wood elements
to produce mature
character
Acetal formation

25. Oak species – American / European

26. Oak species – American / European

27. Oak species – American / Japanese

28. Oak species – flavor notes
MORE FLAVOR NOTES
QUERCUS ALBA
(AMERICAN)
QUERCUS ROBUR
(EUROPEAN)
QUERCUS MONGOLICA
(JAPANESE)
• GROWS SLOWER
• TIGHTER MEDULLARY
RAYS
• HIGH LACTONE
(COCONUT NOTES)
LEVELS
• VERY HARD
• CHARRED INTERIOR
• SOFTER
• MORE PORUS
• TOASTED
• VARIANCE IN
EXTRACTIVE LEVELS
• EX-WINE, SHERRY
• MIZUNARA OAK
• SOFT
• VERY PORUS
• VERY EXPENSIVE
• CONTROLLED FELLING
• VERY HIGH VANILLIN
LEVELS

29. Killer graph – degradation of immaturityTaste
Maturation
Distillery Character
Immaturity

30. Barrel charring

31. Char levels
1 2
43

32. Killer graph – maturationTaste
Maturation
Distillery Character
Immaturity
Cask
Maturation

33. Pyrolysis
• Heat treatment plays a critical role in maturing distilled spirits.
• Two methods used:
- Toasting (sherry or wine casks) is much milder and takes longer
- Charring (bourbon / rye) is more rapid and aggressive and sets alight the
interior of the barrels to create a carbonized layer of activated charcoal
• The objectives / outcomes are the same:
- Degradation of wood polymers to yield flavor compounds, such as lignin
to produce aromatic aldehydes like vanillin
- Degradation of polysaccharides (cellulose / hemicellulose) which help form
maltol which gives rich caramel notes
- Destruction of resinous / unpleasant aromas – pyrolysis removes trans-2-
nonenal which gives a rancid flavor to the spirit
- Production of an active carbon layer – carbon works by a process called
adsorption trapping larger sulphur compounds like DMS (Dimethyl
Sulphide) that give off ‘vegetal’ notes to the spirit

34. Pyrolysis
CARAMELIZATION OF POLLYSACCHARIDES

35. Water and whiskey

36. Taste samples 3-7

37. BULLEIT RYE – O M
BULLEIT RYE – 4 M
BULLEIT RYE – 25 M
BULLEIT RYE – 55 M
BULLEIT RYE – 134 M
BULLEIT RYE – FINAL
Ethyl acetate
Ethyl acetate
3-methyl-1-butanol3-methyl-1-butanol
Ethyl octanoate
Beta-damascenone
Beta-damascenone
Ethyl octanoate
2-methyl 1-propanol
2-methyl 1-propanol
E-nose data for sample 3 – Bulleit Rye barreled
April 2015, aged 4 months

38. BULLEIT RYE – O M
BULLEIT RYE – 4 M
BULLEIT RYE – 25 M
BULLEIT RYE – 55 M
BULLEIT RYE – 134 M
BULLEIT RYE – FINAL
Ethyl acetate
Ethyl acetate
3-methyl-1-butanol3-methyl-1-butanol
Ethyl octanoate
Beta-damascenone
Beta-damascenone
Ethyl octanoate
2-methyl 1-propanol
2-methyl 1-propanol
E-nose data for sample 4 – Bulleit Rye barreled
July 2013, aged 25 months

39. BULLEIT RYE – O M
BULLEIT RYE – 4 M
BULLEIT RYE – 25 M
BULLEIT RYE – 55 M
BULLEIT RYE – 134 M
BULLEIT RYE – FINAL
Ethyl acetate
Ethyl acetate
Ethyl octanoate
Beta-damascenone
Beta-damascenone
Ethyl octanoate
2-methyl 1-propanol
2-methyl 1-propanol
3-methyl-1-butanol3-methyl-1-butanol
E-nose data for sample 5 – Bulleit Rye barreled
July 2011, aged 55 months

40. BULLEIT RYE – O M
BULLEIT RYE – 4 M
BULLEIT RYE – 25 M
BULLEIT RYE – 55 M
BULLEIT RYE – 134 M
BULLEIT RYE – FINAL
Ethyl acetate
Ethyl acetate
Ethyl octanoate
Beta-damascenone
Beta-damascenone
2-methyl 1-propanol
3-methyl-1-butanol3-methyl-1-butanol
Ethyl octanoate 2-methyl 1-propanol
E-nose data for sample 6 – Bulleit Rye final bottled
product

41. E-nose data aged wheated Bourbon
41
Ethyl acetate
Ethyl acetate
3-methyl-1-butanol3-methyl-1-butanol
Ethyl octanoate
Beta-damascenone
Beta-damascenone
Ethyl octanoate
2-methyl 1-propanol
2-methyl 1-propanol

42. Color and pH progression
Sample Color (WCU) pH
Unaged Bulleit Rye – 0 Months 0 4.81
2015 Bulleit Rye – 4 Months 98 4.73
2013 Bulleit Rye – 25 Months 167 4.63
2011 Bulleit Rye – 55 Months 251 4.50
2004 Bulleit Rye – 134 Months 241 4.40
Bulleit Rye – final bottled product 178 4.10
• Rapid color development occurs until ~4.5 years
• Continuous drop in pH during maturation generally yields softer, fuller,
rounder flavor profiles

43. E-nose – principal component analysis
Bulleit Rye 4 mos
Bulleit Rye new make
Bulleit Rye 25 months
Bulleit Rye 55 mos
Bulleit Rye final product
Wheated bourbon
final product
Bulleit Rye
134 mos
Wheated
bourbon new
make
Bulleit chemical ‘signature’ versus wheated bourbons
As whiskeys age, they takes on a different chemical /
sensory profile or ‘signature’

44. Impact of aging on flavor
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1,400,000
AreaCounts
Volatile Compounds in Bulleit Distillates
New make
2013
2004
Final Product
1 propanol ethyl acetate 2-methyl
1-propanol
beta
damascenoneAlcoholic,
fruity, pungent
Butter,
caramelized,
fruity orange,
pineapple,
sweet
Alcoholic, leek,
licorice, winey
Apple, apple
rose, fruit,
honey, sweet
tobacco
• Aging increases fruity, caramelized, sweet, wine / alcohol, honey and
tobacco type flavor compounds
• Aging decreases fermented, ripe, pungent notes

45. Science of location – rickhouse 101
Floor 1 Stitzel-Weller Rickhouse

46. Science of location – rickhouse 101
7
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
6
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
5
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
4
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
3
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
2
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
1
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
HOT AND DRY = PROOF RAISES
COOLER AND MORE AMBIENT MOISTURE = PROOF LOWERS
HEATRISES
ANGEL’S SHARE ANGEL’S SHARE

47. Thank you – Bulleit Rye barreled 2004, aged 134
months

48. BULLEIT RYE – O M
BULLEIT RYE – 4 M
BULLEIT RYE – 25 M
BULLEIT RYE – 55 M
BULLEIT RYE – 134 M
BULLEIT RYE – FINAL
Ethyl acetate
Ethyl acetate
Ethyl octanoate
Beta-damascenone
Beta-damascenone
2-methyl 1-propanol
3-methyl-1-butanol3-methyl-1-butanol
Ethyl octanoate 2-methyl 1-propanol
E-nose data for sample 8 – Bulleit Rye barreled
2004, aged 134 months