Maturation

Question 1

What is meant by the term ‘Angels’ Share’?

Answer 1

The part of the spirit that evaporates each year during oak/wood maturation.

Question 2

What does ASB stand for?

Answer 2

American Standard Barrel

180-200L / 50-53 US gallons

Question 3

Aside from drying outside naturally, where else can staves be dried?

Answer 3

In a wood kiln, which is much faster.

Question 4

Besides flavors, aromas, and color, what else can a spirit extract from a barrel?

Answer 4

Tannins

Add bitterness or a grippy, drying effect on the palate

Question 5

Define esterification

Answer 5

During maturation, which can take place in both wood and inert vessels, fatty acids and alcohols react with each other to form new esters.

For spirits destined for long aging, a distiller may intentionally leave a higher level of Group 3 fractions for added flavor development over time.

Question 6

Evaporation can have a major impact on what?

Answer 6

The concentration of aromas and textures.

Question 7

For an aging spirit, what happens to alcohol levels over time in a dry, less humid environment?

Answer 7

Alcohol levels rise in a spirit barrel.

In a dry environment, water is lost at a faster rate than ethanol.

Question 8

For an aging spirit, what happens to alcohol levels over time in a damp, more humid environment?

Answer 8

Alcohol levels will fall over time.

In a humid environment, water evaporates more slowly compared to ethanol, and as a result, the alcohol by volume (abv) falls.

Question 9

What is a Foudre?

Answer 9

A large wooden vat capable with a volume of 10,000 L / 2,641 US gallons.

Question 10

What is a Hogshead?

Answer 10

Remade ASB barrel

250 L / 66 US gallons

Question 11

How can the size of a barrel impact the extraction rate of color and aroma from the barrel?

Answer 11

The smaller the barrel, the higher the extraction rate, due to the ratio of the surface area of the wood to the volume of the liquid in the barrel.

Question 12

How long can it take for staves to fully dry?

Answer 12

At least a year, but can take up to three years.

Question 13

Examples of inert vessels:

Answer 13

• Glass
• Stainless steel
• Pottery
• Earthenware

Question 14

Effects of maturation in inert vessels:

Answer 14

• Color will not typically change over time
• Flavors and textures will change after a few months or years, becoming smoother, richer, and more complex.

Question 15

Oak alternatives

Answer 15

Oak fragments: chips, cubes, staves, mini-staves

The quality of oak flavor, lack of oxygen esterification, and poor concentration of flavors over time can be the result of the use of alternatives rather than barrels.

Question 16

On a volume basis, how much spirit can be soaked up by an oak barrel?

Answer 16

There can be several liters of spirit absorbed into the barrel staves at any given time of maturation.

Question 17

What causes oxidation?

Answer 17

Oxygen interacting with components of the spirit inside the barrel.

Question 18

Oxygen interacting with components of the spirit inside the barrel can result in what?

Answer 18

Oxidation

Question 19

What are pipones?

Answer 19

Very large barrels

20,000 L / 5,283 US gallons

Question 20

What is preservation (maturation)?

Answer 20

• The practice of moving very old spirits into inert vessels in order to preserve them in their current state
• This is done for blending needs and other historical references

Question 21

What is rancio?

Answer 21

A tasting term to describe the floral, nutty, dried fruit and pungent spicy / tobacco notes in long-aged spirits. It is indicative of oxidative aging.

Question 22

What is re-barreling?

Answer 22

Moving a spirit from one barrel to another to get a different effect or build complexity, and can be used to slow down the extraction rate and not overpower a spirit with wood.

Question 23

What volume does a Sherry Butt hold?

Answer 23

500 L / 132 US gallons

Question 24

Size of a typical Cognac barrel?

Answer 24

300 L / 79 US gallons

Question 25

The **color** a cask can give a spirit is **dependant** on what?

Answer 25

The type of **heat treatment** the barrel received. ## Footnote *i.e.: Charring can give more color*

Question 26

What are the **five** stages of barrel production?

Answer 26

1. **Cutting** 2. **Drying - usually done outdoors** 3. **Shaping/bending and heating** 4. **Toasting** 5. **Charring**

Question 27

The **hottest** part of an aging warehouse?

Answer 27

**Top floors** - heat rises.

Question 28

The most commonly-used species of **American Oak**:

Answer 28

**Quercus alba** ## Footnote *White oak*

Question 29

The two important **species** of European oak?

Answer 29

1. **Quercus Petraea** 2. **Quercus Robur**

Question 30

To what strength are spirits diluted **before wood aging**, and why?

Answer 30

Typically to between **60-63 % abv** ## Footnote *Because high strengths will extract too many unwanted flavors from the wood due to the ethanol.*

Question 31

# **True / False:** A spirit sits **passively** inside an oak barrel.

Answer 31

**False** ## Footnote *A spirit is **continuously moving** into and out of the wood.*

Question 32

# **True / False:** Barrels are **watertight**, but not **airtight**?

Answer 32

**True** ## Footnote ***Gases** are able to move into the barrel, while components of the spirit are able to **evaporate** through the wood.*

Question 33

Typical **aromas** of Quercus alba?

Answer 33

**Vanilla**, **clove**, **sweet spice**.

Question 34

What are some of the **considerations for choosing** an oak barrel to age a spirit?

Answer 34

* **Species** of oak * **Size** of the barrel * **Age** of the barrel * Previous **contents** * Fill **strength** * **Temperature** * **Humidity** * **Time** the spirit will be in the barrel

Question 35

What are the **two broad categories** of oak species?

Answer 35

Those native to **North America** and those native to **Europe.**

Question 36

What are the **two groups of interactions** that oak can perform?

Answer 36

1. Interactions between the spirit and the **oak** 2. Interactions between the spirit and the **environment**

Question 37

What are the two most important types of **vessels** used for spirit maturation?

Answer 37

**Oak** and **inert vessels**

Question 38

What can a spirit left to **age for decades** be used for by a distiller?

Answer 38

Used in **small amounts** to add **flavor** or **character** to a blend.

Question 39

What can heating the inside of a barrel do, besides imparting some flavors?

Answer 39

Can **remove** undesirable flavors.

Question 40

What does **drying** the staves result in?

Answer 40

Drying **removes water,** as well as **undesirable aromatics** present in freshly harvested oak.

Question 41

What does oxidation **result** in?

Answer 41

It produces a large number of **new chemicals**, many of which are **aromatic** and can play a big factor in the flavor of the final product, including adding **rancio**.

Question 42

What is **char**?

Answer 42

A **layer of carbon** on the inside of the barrel, which has resulted from setting the wood on fire.

Question 43

What is done to **refresh** a barrel for use?

Answer 43

The inside is **scraped out** to expose new wood, and then it is **re-charred.**

Question 44

What is **lost** during spirit evaporation?

Answer 44

Mostly **water** and **ethanol**, but some other components may also be lost, such as Group 1 fractions.

Question 45

What is one reason European oak may be **less overt** in the spirit than, say, the wood used for American whiskey?

Answer 45

The aromas **are often restrained** due to the use of a combination of new and used staves to build the barrels used for European-based spirits.

Question 46

What is the basic result of **time** **aging** for a spirit?

Answer 46

**Concentration** of flavors and aromas, and more tannic.

Question 47

What is the **color progression** of a spirit as it matures in oak?

Answer 47

* **Clear** * **Pale Lemon** * **Gold** * **Amber** * **Brown**

Question 48

What is the definition or purpose of **maturation**?

Answer 48

Maturation is intended to make a **positive change** to the **aroma**, **texture**, and, in some cases, the **color** of the spirit.

Question 49

What is the most **commonly-used** type of **wood** for distillery vessels?

Answer 49

**Oak**

Question 50

What is **toasting**?

Answer 50

* The **gentle heating** of the barrel over several minutes, resulting in it becoming blackened. * Most closely associated with **European** barrel production

Question 51

What kind of interaction is **char** known as?

Answer 51

**Subtractive**

Question 52

What kind of **interaction** is **oxygen** known as?

Answer 52

**Interactive**

Question 53

What **kind of spirits** have vanilla, coconut, clove, and sweet spice aromas?

Answer 53

**Wood-aged spirits**

Question 54

What kind of **structure** does the surface of charred wood have?

Answer 54

**Irregular**, and as a result, is able to **remove/trap** some of the components of the spirit, thus making it **smoother**.

Question 55

What part of the tree is **most important** to the cooper?

Answer 55

The **trunk**, but not the sapwood.

Question 56

What type of cellars does one find in **Cognac**?

Answer 56

**Dry** and **Wet** ## Footnote *In dry cellars, the alcohol levels go up over time resulting in an angular structured style of spirits, while the opposite happens in wet cellars, with a softer style of spirit being the result.*

Question 57

Where are staves **traditionally** dried?

Answer 57

**Outdoors** in order to dry naturally.

Question 58

Where do the wood aromas come from in a barrel?

Answer 58

Some come from the **wood itself**, while others are a result of the **heat treatment.**

Question 59

Where does the **color**, **flavor**, and **texture** of oak come from?

Answer 59

**Molecules** within the structure of the wood.

Question 60

Which can impart **more** flavors: **new** or **older** barrels?

Answer 60

**New barrels** will impart much more flavor than used barrels.

Question 61

Why are Bourbons typically aged in wood for a **shorter period of time** than Scotch Whisky?

Answer 61

**Warmer temps** in Kentucky **increase** the **extraction** rate of color and aromas from the wood, much quicker than in Scotland.

Question 62

Why do spirits **lose** some volume each year in a barrel?

Answer 62

Because of **evaporation**.

Question 63

**Why** is oak the most commonly used type of **wood** for distillery vessels?

Answer 63

* It is **hard**, **durable**, and sufficiently **flexible** to make into barrels, and it can be made **watertight**. * It also imparts **flavors** that most people find agreeable.

Question 64

Why would a distiller **NOT** use wood for aging their spirit?

Answer 64

Do not want oak flavors taking away from the **purity** of their spirit. ## Footnote *Inert vessels will be used - such as for vodka, fruit spirits, gins, Tequila Blanco, etc.*

Question 65

**Wood polish** and **sweet spices** are more prominent in which type of oak?

Answer 65

**French oak**