Maturation Flashcards
How does oxidation change the aromas of wines
Gradual reduction in primary aromas
Development of tertiary aromas - dried fruits, nuts
How does oxidation influence the colour of white wines
White wines become darker, becoming gold then brown
How does oxidation influence the colour of red wines
Greater colour stability and intensity
Describe the micro-oxygenation process
Micro-oxygenation involves bubbling oxygen through wine
What is the unit of measurement of oxygen during micro-oxygenation
Units of mg/L per month
What vessels is micro-oxygenation usually carried out in?
Stainless steel tanks
When does micro-oxygenation occur and how long does it last for?
Micro-oxygenation occurs post alcoholic fermentation
It is carried out for a number of months
What effect does micro-oxygenation have on wines
Increases colour stability and intensity
Softens tannins
Improves texture
Reduces the presence of unripe, herbaceous flavours
What temperatures are white wines usually stored at after fermentation?
White wines - 8-12C
What temperatures are red wines usually stored at after fermentation?
Red wines - 12-16C - less susceptible to oxidation
What are the ideal conditions for wine when it is being matured
Matured in cool cellars of constant temperature and humidity
Temperature and humidity control systems are common in modern cellars
Traditional cellars built underground for this reason
What features of wooden vessels influence the level and type of compounds extracted from wood vessels during maturation
Age of the vessel
Size of the vessel
Type of wood
Production of the vessel
Length of time in wood
Oak Alternatives
How much new oak flavour is lost by a barrel after its first year of use
50%
By the time the vessel is on its ______ usage, it will contribute very little at all
Fourth
American oak contains much higher levels of _______, which give aromas of ________.
Lactones, coconut
A more tightly grained wood is the result of ______ growth of the tree.
Slower
Wood with a tight grain ______ down the extraction of compounds compared to more coarsely grained wood.
Slows
European oak must be ______ to create staves, whereas American oak can be ______.
Split, sawn
Where is the oak used to create oak barrels seasoned
Outside for 2-3 years
Describe the barrel production process
Involves heating staves so they can be bent into shape
What are the toasting levels for oak barrels
Light
Medium
Heavy
What flavours/aromas does toasting contribute to wine
Spice
Caramel
Roasted nuts
Char
Smoke
What is lees and what is it made up of?
Lees is the sediment that settles at the bottom of a wine vessel
It is made up of:
Dead yeast
Dying yeast
Bacteria
Grape fragments
Precipitated tannins
Nutrients
Insoluble compounds
What is gross lees
Gross lees is the sediment that forms quickly after the end of fermentation - within first 24 hours
What is fine lees
Smaller particles that settle more slowly and gradually form sediment
How are lees removed from a vessel?
By racking
First racking removes gross lees
Subsequent rackings handle fine lees
Describe the autolysis process
After fermentation, yeast cells die very slowly and break down releasing compounds that contribute flavours, body and texture to wine
What benefits does lees ageing have on white wines?
Helps in stabilization of white wines against unstable proteins that can cause hazes
Helps protect wine from oxygen
Helps maintain a slow, controlled oxidation during maturation
Lowers need to use SO2 during this time
If layer of lees becomes too thick, what compounds can it produce?
Volatile, reductive compounds
Aromas of struck match and smoke
If not controlled - smell of rotten eggs
List different blending wine options
From different grape varieties
From different locations
From different grape growers/businesses
From different vintages
Treated differently in winery
Treated equally in winery but in different vessels
List the 7 key reasons for blending wine
Balance
Consistency
Style
Complexity
Minimize faults
Volume
Price
