WSET Diploma D1 Maturation CH14 Flashcards
When does Maturation occur and why would maturation occur
When would maturation not occur
Occurs after Fermentation and Malolactic Conversion (if allowed)
Before finishing and packaging
For quaility or style of wine
Not occur for style of wine, fresh fruity whites
What are key factors to maturation that can effect the wine
What can happen at anypoint of the winemaking process but often occurs after maceration and before finishing and packaging
- Oxygen
- New Wood
- Yeast Lees
- Blending
How does oxygen affect wine during maturation
What factors influence speed of oxidation
- Influences quality and style because impacts aroma and phenolic compounds
- Gradual reduction of primary aromas, if primary develops into tertiary marks ability to age.
- Maintain or enhance quality of wine
- Influence color, giving young red wine color stability (important in light reds)
- Soften tannin, positive for quality
Speed of oxidation influenced by
- Amount of oxygen
- Temp (warmer increases oxygen reaction)
Oxygen exposure in maturation Red vs White
Red can withstand more oxygen usually matures 12 - 24 months as opposed to white 6 - 12 months
Can be required for certain styles
Oxygen and Wood
When is oxygen exposed to wine in wood
“Angel share”
Barrels can be expensive
slowly gradual exposure to oxygen in wood
oxygen released from pores in the vessel
most exposure during racking, lees stirring and topping when bung is removed
What is micro-oxygenation
Why is it used
How is it done
Bubbling oxygen through the wine
Cost Effective, Inexpensive to mid priced wines, growing in premium and super premium
- Increase color stability
- Soften tannins
- improve texture
- reduce underipe herbaceous flavours
- can be controlled more than barrel
- Integrate oak with oak alternatives
Usually done in stainless months after fermentation
Dis
Increasing oxygen can increase spoilage bacteria
Relatively new
Aside from Oxidation, how does wood effect wine
When selecting wood for maturation, what factors come in to play (types of compounds) and how do they effect wiine
- Contain extractable compounds
Tannin and Aroma
1) Age of Vessel - new wood more extractable compounds, barrel losses about 50% after first use, nutral at 4th. Still allows oxygen, usually blend new and used because used is too powerful
2) Size of Vessel - Smaller vessel, more wine surface area, more oxygen exposure
3) Type of Wood - Oak most common, easliy shaped water tight. Positive aromas/flavors. Difference American-lactones (cocunut)
Chestnut, Cherry and Acacia occasionally used
4) Production of Vessel - Seasoning wood, 2 - 3years. Lowers humidity and bitter flavors. Heating staves, toasting - length of heat exposure. Wide range, light medium or heavy toasts. Spice carmel roasten nuts or char
How does Length of time in wood effect the wine
- Longer increases extraction of compounds
- Longer greater exposure to oxygen
- Longer greater diversity, not all components extracted at same time
What costs come with maturation in wood
Expensive so usually mid - premium - super premium wines
- Barrels are expensive
- Monitoring, lees stirring, racking all labor intensive
- Meticulous cleaning because spoilage bacteria like to live in wood
- Slow process, takes space and time to store and age
What are oak alternatives, when are they used
Adv and Dis
Used for inexpensive - mid priced wines when the flavors of oak are desired.
Oak chips or oak staves attached or float in vessel (Stainless or concrete)
Adv
- Can be added to large tank
- Less labor intensive
- Cheaper than barrel
- Quick effect
- Can be used with micro-oxygenation
Dis
Style depends on source, size, toasting and if micro-oxygenation is used
What is the role of Lees in Still Wine Maturation
Lees vs Gross Lees
When are gross lees removed
- After fermentation yeast cells die slowly (autolysis) releasing compounds and contributing flavors
Bind with phenolic compounds - Reduce color
- Soften tannin
- Also bind with other extractable components (wood tanins and flavors)
- Reduce astringency
- Helps stablize white wine
- Lees flavor/aromas - yogurt, biscuit, toasted bread
- Lowers need of SO2
- Encourage lactic acid bacteria
Sediment in bottom of vine vessel, the sediment formed at the end of fermentation is called gross lees - larger heavier particles
(Made of dead yeast, dying yeast and bacteria, grape fragments, precipitated tannins, nutrients and other insoluble compounds)
Gross lees usually removed first racking
What negative effects can lees have on Wine
Other disadvatages to lees maturation
If not controlled, unpleasant aromas, rotten egg, encourage spoilage bacteria
The cost of keeping in the winery creates cost, stirring - manual labor if large number of barrels need to be stirred
What is racking
Goals of racking
Transferring wine from one vessel to another
To filter out sediment, gross lees, fine lees
Oxidative process
What is blending in winemaking
When is blending most commonly carried out
What are 6 key goals (reasons) of blending
Mixing together two or more batches of wine
Usually carried out before stabilisation, finishing and packaging
Goals: Balance Style Complexity Minimize Faults Volume Price
How can blending occur in winemaking
- Different grape varieties
- Different locations (vineyards, regions, countries)
- Different growers, or businesses that sell grapes, must or wine
- Different vintages
- Wines that have been treated differently at winery
- Wines that have been treated equally in different vessels for logistical reasons
