Chapter 14 - Maturation

Question 1

Pros of Oxidation during Maturation

Answer 1

1. Development of desired tertiary aromas (increases complexity)
2. Stabilizes and intensifies color in reds (anthocyanins and tannins bind together) so its not bleached by SO2 or absorbed by the lees
3. Softens tannins

Question 2

Key factors during maturation that affect wine style:

Answer 2

1. Wood
2. Oxygen
3. Lees

Question 3

What is micro-oxygenation?

Answer 3

An alternative to barrel aging that is cheaper and works by bubbling O2 through wine. Generally carried out in stainless steel tanks for a number of months.
Benefits:
Softens tannins
Stabilities color and intensity
Improves texture
Reduces presence of unripe herbaceous flavors
Quicker exposure to O2 than barrel (still gentle though)
Rate of O2 exposure is controllable
Can be used with oak chips or staves

Question 4

How big are barriques?

Answer 4

225L

Question 5

American vs European Oak

Answer 5

European:
Significant vanilin level
Imparts more tannins
Cost more to make because must be split to create staves
Tighter grains (slower growth)

American:
Significant vanilin level
Significant lactones level (coconut aroma)
Impart a greater intensity of aromas and flavors
Cost less to make because can be sewn, which means more can be made with the same amount of wood
Grows significantly quicker (coarse grains - faster extraction of compounds)

Question 6

Why is it important to season wood?

Answer 6

Takes 2-3 years
Lowers humidity
Reduces bitter flavors
Increases aroma compounds

Question 7

Toasting definition and contributions

Answer 7

Temperature and length of heat exposure
Makes the staves bendable into barrels
Transforms tannins and aroma compounds
Contributes notes of spice, caramel, roasted nuts, char, and smoke
Many cooperages have a "house style"

Question 8

Why is barrel aging expensive?

Answer 8

1. If small barrels are used, many will be needed
2. Higher risk of microbial spoilage so barrels always need to be kept meticulously clean (ie brett)
3. Racking, lees stirring is individualized for each barrel and becomes labor intensive
4. Slow process that takes up the barrel for a long time

Question 9

What is lees composed of ?

Answer 9

Dead yeast
Dying yeast and bacteria
Grape fragments
Precipitated tannins
Nutrients
Other insoluble compounds

Question 10

Why age on lees?

Answer 10

1. After autolysis, compounds are released that contribute flavor, body, and texture. It provides yogurt, dough, biscuit, toasted bread notes.
2. It can bind with phenolic compounds to reduce color and soften tannins.
3. It can bind with wood tannins and flavors and reduce astringency and modify wood flavors
4. Stabilizes white wine against unstable proteins that cause haze
5. Protect the wine from O2 - Maintains a slow, controlled oxidation during maturation and loweres need for SO2
6. Provides nutrients for lactic acid bacteria and promotes malo
7. Introduce reductive sulfure compounds

Question 11

What are gross lees?

Answer 11

Sediment that forms quickly after the end of fermentation (within 24 hrs). These are heavier, larger particles

Question 12

Cons of Lees Aging:

Answer 12

1. Increases time the wine is stored at the winery before release (becomes costly)
2. If the layer of lees is too thick, it can produce volatile, reductive sulfur compounds
3. Provides nutrients for spoilage microbes (ie Brettanomyces)
4. Wine needs to be monitored regularly adn stirred regularly - labor costly

Question 13

What is racking?

Answer 13

Transferring wine from one vessel to another with the aim of removing sediment. Can be an oxidative process

Question 14

Why do winemakers blend?

Answer 14

For: Balance
Consistency
Desired Style
Complexity
To minimize falts
For volume (poor vintages, small holdings)
Price (blend well known and lesser known, cheaper grapes)