Maturation and Post-Distillation Flashcards by Jill Goldstein

What is lignin?

A “glue-like” substance in oak that helps cement the fiber cells in the wood together. Also the source of methoxyphenols in oak that provides vanilla and smoke aromas.

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What is Hemicellulose in oak?

An organic compound responsible for the red layer that forms in charred barrels. It contains many different sugars easily soluble in alcohol.

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What does cellulose provide in oak?

Structural integrity and chemical resistance. Sometimes called the skeleton.

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What are extractives in oak?

Organic compounds present in wood in tiny amounts, including gums, resins, waxes and tannins.

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What percentage of oak is made up of extractives?

5-10%.

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What are some extractives found in oak?

Gums, fats, resins, waxes, oils, starches, coconut-scented lactones, volatile phenolic acids, tannins.

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What percentage of oak is lignon?

25-30%

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What percentage of oak is hemicellulose?

20-30%

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What percentage of oak heartwood is cellulose?

40%

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What are the three main structural component of oak?

Cellulose, hemicellulose, and lignin.

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Is French or American oak tighter grained?

French oak.

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What is Quercus Alba?

The species name for American oak.

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What is the genus for oak?

Quercus.

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What is the name of the process included in oak aging the adds aromas of chocolate, butterscotch and caramel to the spirit?

Extraction

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What is the part of oak aging that occurs due to the semiporous character of the wood?

Oxidation and concentration.

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What part of oak aging occurs due to the presence of charcoal from charring?

Filtration

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What process during oak aging results in the “angel’s share”?

Evaporation.

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What occurs during the oak aging process due to the degrading of the tannins of the wood?

Coloration.

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What is the typical annual loss of liquid due to oak aging?

Approximately 3% per year, higher in warmer climates.

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What is the effect of a humid climate on evaporation during the oak aging process?

In areas of high humidity, the spirit evaporates faster than the water, resulting in lower proof.

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What is the effect of a dry climate on evaporation during the oak aging process?

In drier regions, the water loss is greater than the spirit loss, resulting in higher proofs.

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What are the burn times for the four main levels of char?

Level 1 - 15-second burn
Level 2 - 30-second burn
Level 3 - 45 second burn
Level 4 - 55 second burn

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What is the term sometimes applied for a level 4 char?

Alligator char.

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What is thermal degrading?

The term used for the toasting and charring of the inside of wood barrels.

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How many bottles will come from a single barrel or cask?

100-300, depending on barrel size.

What are some of the benefits of using American Oak for aging spirits?

Strength Resiliency Ability to bend High tannin content (resistant to insects/fungus) Leak proof yet breathable.

What are the processes involved in oak maturation?

Extraction Evaporation Oxidation Concentration Filtration Coloration

What is a Demijohn?

A glass or plastic container that may be used to hold wine or spirits at some point during the maturation process. Also called a bonbonne.

What is a Bonbonne?

A glass or plastic container that may be used to hold wine or spirits at some point during the maturation process. Also called a demijohn.

What are two ways staves are dried before being made into barrels?

Outdoors (can take 1-3 years) In a kiln.

What is the difference between toasting and charring?

Toasting is heating gently for several minutes. Charring involves heating the barrel until it catches fire, and allowed to burn for a very short time.

What are the main effects of a spirit's interaction with oak?

Added Color Added Aroma Adding texture Removing coarse textures.

What are some of the aromas added from oak?

Vanilla Coconut Clove Sweet spices

What textures are added to a spirit from oak?

Bitterness, astringency, and drying of the mouth. Caused by the tannins in oak.

How are coarse textures removed from a spirit during maturation in wood?

If the barrel is charred, the irregular surface traps some of the coarse textured components (such as fusel alcohols) from the spirit.

What are the effects on a spirit of the interaction with the environment during maturation in wood?

Added aromas and flavors Evaporation Concentration

What are some of the aromas and flavors added to a spirit during wood maturation?

"Rancio" characteristics, such as wood polish, earth, leather, tobacco, wet leave, forest floor.

What undesirable fractions may be lost during maturation in wood due to evaporation?

Group 1 fractions.

What are the two most important species of European oak?

Quercus petraea Quercus robur

What aromas are more prevalent in French oak than American oak?

Wood polish Sweet spices

What textural characteristic is more common to spirits aged in French oak over American oak?

Higher level of tannins.

What is the size of an American Standard Barrel?

180-200 L (48-53 gallons)

What is the size of a Hogshead?

250 L (66 gallons)

What is the size of a Cognac barrique?

300 L (79 gallons)

What is the size of a Sherry Butt?

500 L (132 gallons)

What is the size of a Foudre?

1,000-10,000 L (264-2642 gallons)

What is the size of a Pipon?

20,000 L (5283 gallons)

What is a danger of using barrels that have not been dried out with wine absorbed into the staves?

Sulfur taint.

What can be a problem if distillers fill barrels with spirits at distillation strength?

The abv can be so high that the amount of compounds extracted from the oak has a negative impact on the flavor and texture of the spirit.

To what abv are most spirits reduced prior to maturation in wood?

60-64% abv

What is unique about Maker's Mark's barrel storage?

The barrels are rotated between warm and cool floors to even out the differences in storage.

What is esterification?

A change where the fatty acids and alcohols continue to react with each other to form new esters.

Why might a distiller include more Group 3 fractions in a spirit destined for long ageing?

To add character to some longer aged spirits such as XO cognacs and long-aged rums.

What are the four main considerations when deciding the type of barrel for the maturation of spirits?

Type of oak Barrel size Heat treatment (charred or toasted) Barrel age

Why is there a more dynamic approach to barrel decision making in Cognac production?

Since production only occurs once a year, distillers have more time to make such decisions. A variety of spirits are made as well, requiring variations in maturation.

Why is there a more dynamic approach to barrel decision making at the Middleton distillery in Ireland?

Since a wide variety of spirits are made, they must have a large number of different types, ages, and barrels to blend.

What are four common formats for oak alternatives?

Chips Cubes Mini staves Full staves

What do some distillers do to increase the reaction with oxygen of a newly made spirit when placed in an inert vessel?

Leave a small amount of space at the top so that oxygen can react with the spirit.

What flavors and textures can change and develop when a spirit is stored in an inert vessel?

Esterification Textures can become smoother and more mouth-filling.

Where is the storage of spirits in inert vessels to stop further development most commonly used?

Cognac and Armagnac

What are the four main phases of post-distillation operations?

Blending Removals (visual imperfections, texture, colors) Additions (Color, aroma, texture, sweetness, water) Packaging.

When does blending occur for most spirits?

Immediately after storage or maturation.

What are the two main reason for blending spirits?

Creating style and complexity Managing consistency.

When are adjustments to color, clarity, sweetness, texture or abv of a spirit usually made?

After blending.

What are the two main methods to remove visual imperfections?

Coarse filtration Chill filtration.

How are char fragments from inside of the barrel generally filtered out from matured spirits.

Coarse filtration (most common) Gravity - occasionally

During chill filtration, what temperature are the spirits chilled at?

14-39 degrees F (-10-4 degrees celcius)

How are textural imperfections removed from spirits?

Carbon (char inside barrels, activated) Lincoln County Process.

How is color removed from spirits?

Activated carbon.

What are some reasons color is added to some spirits?

To achieve consistancy To give customers a specific impression of a spirit. By-product of technique (eg oak aging)

What is another name for the caramel color added to some spirits?

E150a

Does E150a (caramel color) add sweetness to a spirit?

No. It is actually bitter.

How is sweetness generally added to spirits?

Pure sugar products (eg corn, grapes, other plant sources) Syrup barrels.

What are syrup barrels?

Sweetening materials prepared by distillers, basically a very sweet simple syrup.

What might be added to a spirit to produce a smoother texture?

Glycerol and a small amount of sugar.

What are the two ways that distillers reduce their abv prior to bottling?

Water Faibles/petites eaux (aged, low-strength spirit)

What is Faibles/petites eaux?

An aged, low-strength spirit. These are spirits that are diluted to less than 30% abv before being matured in barrels, and are then blended with spirits with higher abvs.

Does the Lincoln County Process happen before or after maturation?

Before maturation

What are the main post-distillation processes?

Adding coloring/other additives Filtration Batching or Blending Bottling.

What does filtration by activated carbon do?

Removes the harsher characteristics of the spirit.

What is chill filtration?

A spirit is chilled, which causes a haze to form that can then be removed.

What are other terms for blending barrels of a spirit?

Batching Vatting