1
Q
How are Young/fruity/aromatic wines
e.g. NZ Sauv B or Veneto Pinot Grigio finished and matured?
A
- wines protected from oxygen during winemaking
- likely to be protected during bottling in order to continue to protect their primary fruit aromas
- e.g. by being stored in vessels which are impermeable to oxygen (stainless steel etc) and blanketed with inert gases (SO2).
- Finished and packaged immediately at end of winemaking process
2
Q
How are bulk wines finished and matured?
A
- if making wine as above, winemaker might wait until has an order before bottling or deciding to ship in bulk
- gives winery flexibility when selling wine during year (can choose to package differently, blend etc)
- gives winery more space (by storing in bulk rather than stacking in bottles)
- wine labels less likely to get dirty or ruined
3
Q
What is post-fermentation maturation and what are the three key influences?
A
- period of maturation post-ferm is essential to give style and quality of wine
- key influences (but may not all be used by winemakers) are:
- oxygen
- new wood
- yeast lees
4
Q
What is the role of blending?
A
- significant impact on style, quality and price
- can take place at any time
- often done at end of maturation process
5
Q
What is the impact of OXIDATION on ‘Aromas’?
A
- gradual reduction in primary aromas
- development of tertiary aromas (e.g. dried fruit, dried nuts)
- can maintain or enhance quality of wine depending on the wines structure
- if primary notes are not replaced by tertiary ones then quality of wine can fade
6
Q
What is the impact of OXIDATION on ‘colour’?
A
- influences colour
- white wines = darker, gold, brown
- red wines = paler, browner
- red wines can have greater colour stability and intensity when exposed to oxygen
- anthocyanins bind with tannins which protects the anthocyanins from being absorbed by yeast lees, or bleached by SO2 additions
- very imp for light coloured wines e.g. Pinot Noir
7
Q
What is the impact of OXIDATION on ‘tannins’?
A
- tannins become softer
- good for quality
- likely to be linked to anthocyanin and tannin bonding
8
Q
What influences the speed of oxidation?
A
- influenced by:
- amount of oxygen exposure
- compounds in wine
- temperature (warm temps increase speed of oxidative reactions)
- if fully exposed to air, wine will oxidise quicker than if had gradual exposure (i.e. in large oak vat)
- red wines can withstand higher exposure due to higher content of anti-oxidative phenolic compounds (tannins) - hence why matured for longer than whites
- 12-24 months for red
- 6-12 months for white
9
Q
What influence does oxidation have on the style of wines produced?
A
- high level of oxidation key to certain styles
- EXAMPLE: Olorosso sherry
- evident from brown colour, lack of fresh fruit on palate
- lots of dried fruit and nuts on palate
- wines stored in not-filled barrels allowing oxygen to fill headspace (ullage)
- too much oxidation in some wines considered a fault
10
Q
Describe the impact of wooden vessels on the oxidative process
A
1) method of slow, gradual exposure to oxygen via small wooden barrels
2) some oxygen comes from pores in vessel within first month that vessel is filled with wine
3) small amount of oxygen continues to pass through gaps between staves and bung hole
*** most exposure comes from any transfer of wine (racking, lees stirring, topping up (when bung removed))
4) some wine generally lost during maturation process in wooden vessels
5) water and alcohol impregnate wood
6) within the staves, water and alcohol turn to vapour and diffuse to air outside the vessel
7) this concentrates other components of wine
*** small vessels have LARGE surface area to volume ratio - INCREASES rate at which wine is lost so need frequent topping up to avoid ullage and over-oxidation
*** frequency of topping up leads to more oxygen exposure in these smaller vessels and, combined with higher surface/volume ratio, leads to quicker oxidation
11
Q
What is micro-oxygenation?
A
- technique that is cheaper than maturing wine in barrels
- involves bubbling oxygen through wine
- dose is in units of mg/L per month
- usually carried out in stainless steel tanks for several months post-alcoholic fermentation
- has been used on inexpensive, mid-priced wine; but now seeing more prem and super-prem wineries using it
- increases colour stability, intensity, soften tannins, improves texture, reduces unripe, herbaceous flavours
- gentle exposure to oxygen without needing expensive barrels
- rate of exposure can be controlled more tightly than in barrels
- can help integrate influence of oak (if used in conjunction with oak alternatives (chips/staves etc))
- still risk of spoilage microbes (Brett and acetic acid bacteria) increases with any form of prolonged oxygen exposure
- not enough research done on this technique to assess the impact on various grape varieties
12
Q
What are the benefits of micro-oxygenation?
A
- increases colour stability, intensity, soften tannins, improves texture, reduces unripe, herbaceous flavours
13
Q
What are the risks of micro-oxygenation?
A
- still risk of spoilage microbes (Brett and acetic acid bacteria) increases with any form of prolonged oxygen exposure
14
Q
why are wines matured at a slightly cooler temperature?
A
- wines matured in stable, cool temps to slow rate of oxidation and lower chance of microbial spoilage
15
Q
What temperatures are white wines matured at?
A
- white wines matured at 8-12 degrees
16
Q
What temperatures are red wines matured at?
A
- red wines matured at 12-16 degrees (less susceptible to effects of oxidation)
17
Q
What is the impact of temperature and humidity on the maturation process?
A
- temps slow down maturation
- warmer temps don’t speed up ageing but determine what reactions can occur and how quickly they do
- low humidity and warm temps increase rate of wine loss
- reduces amount of wine to sell
- need to top up more often
- risk of oxidation increased
- low humidity (under 70%) causes water to be lost at greater rate than alcohol which can lead to greater alc concentration in wine
- hence needing to keep constant temp and humidity
18
Q
Newly made wood contains…
A
extractable compounds (inc tannins and aroma compounds) which can influence wine
19
Q
What impact does the age of a wooden vessel have on the maturation process?
A
- new wood contains extractable compounds
- amount of extraction decreases with each use (loses 50% of new oak flavours in first year)
- by 4th use, will impart little flavour but will allow oxygen
- if don’t want new oak flavours to impact wine, winemakers will use pre-used barrels
- will sometimes blend wine matured in new and old oak to balance flavours
20
Q
What is the size in litres of an oak barrique?
A
225L
- hold small volume of liquid compared to surface area of vessel
- any extraction from wood and exposure to oxygen is greater than in large vessels
21
Q
What are the four wood influences we need to consider?
A
- Oak
- European Oak
- American Oak
- tightness of grain
22
Q
What impact does ‘oak’ have?
A
- can be easily shaped into barrels and make containers watertight
- has positive effects on aromas/flavours and structure of wine
- can also use chestnut, cherry, acacia wood as well
23
Q
What impact does ‘european oak’ have?
A
- French, Hungarian, Russian, Slavonian
- contains significant levels of VANILLIN
- imparts more tannin
- more expensive production process
- French barrels more expensive (€600-€1200)
- French wood must be split to create staves to create barrels
24
Q
What impact does ‘american oak’ have?
A
- contains significant levels of VANILLIN
- contains higher levels of lactones (coconut aromas)
- imparts greater intensity of aroma/flavour than European oak
- less expensive production process
- cheaper (€300 - €600)
- wood can be sawn so more vessels can be made from same amount of oak
- grows quicker than European oak
25
What impact does the 'tightness of grain' have?
- more tightly grained wood is result of slower growth of trees
- e.g. oak trees grown in Russia/Hungary grow slowly and have tightest grains
- tight grains slows down extraction compounds compared to coarser grained wood and can alter what compounds can be extracted
- Hungarian oak (tight grain) gaining popularity in NY State as allows gradual extraction of oak aroma compounds and tannins for red wines so don't end up dominated by oak
26
How is wood seasoned?
- done outside
- takes 2-3 years
- lowers humidity levels in wood
- reduces bitter flavours
- increases some aroma compounds (e.g. flavour of cloves)
27
How is a barrel produced?
- heat staves so can be bent into shape
- heating transforms tannins and aroma compounds in oak
- temperature and length of heat exposure referred to as TOASTING
- barrels either light, medium or heavy-toasted
- toasting gives notes of spice, caramel, roasted nuts, char, smoke
- cooperages produce barrels with 'house style' (seasoning, wood, toasting) so winemakers may choose range of barrels from different cooperages to maximise blending options
28
What are the cons to barrel maturation?
- expensive
- only really used for mid-priced, prem or super-prem
- barrels are expensive to buy
- small barrels don't hold that much liquid so need a lot of them
- monitoring wine in separate barrels and performing winemaking operations is labour intensive
- need good sanitation to prevent microbial spoilage
- maturation is a slow process so ROI is slow
29
What are two possible oak alternatives?
- Oak chips
| - oak staves
30
How are Oak Chips used in wine?
- placed in permeable sack and left to soak in wine
31
How are oak staves used in wine?
- attached inside stainless steel or concrete vessel
| - can also float in wine
32
What are the benefits of oak alternatives?
- can purchase different styes of wood, seasoning and toasting levels
- cheaper than purchasing barrel
- can be added to large tank of wine (less labour intensive)
- quick to have an effect
- can finely tune desired style of wine
- can use micro-oxygenation alongside to get gentle oxidation of barrel maturation
33
What are lees and what six things are they made up of?
- sediment that settles at bottom of a wine vessel
- made up of
* dead yeast,
* dying yeast and bacteria,
* grape fragments,
* preciptated tannins
* nutrients
* other insoluble compounds
34
What are gross lees?
- sediment that forms quickly after end of fermentation (within 24 hours)
- larger, heavier particles
35
What are fine lees?
- smaller particles
- settle more slowly
- gradually form sediment
36
How do you remove lees from still wine during maturation?
- removed by racking
- first rack post-ferm removes gross lees
- subsequent racking removes fine lees
- some leave wine in contact with lees to get flavour profile
- post-ferm, yeast cells die slowly and break down (autolysis) which give compounds which contribute flavours, body and texture to wine
- some compounds bind with phenolic compounds in grapes which reduce colour and soften tannins
- compounds also bind with extractable components from wood (wood tannins and flavour) which reduce astringency and modify flavours from wood
- in white wines, likely to get aromas of yogurt, dough, biscuit, toast etc
37
What is the impact of lees on the ageing process?
- helps with stabilisation of wine against unstable proteins which cause hazes
- more significant impact in white wine and gross lees cause more impact than fine lees
- increases time wine is stored in winery before release so increases cost of final wine
- ageing on lees needs close monitoring and may be stirred (labour cost)
38
What role do lees play in protecting wine during the maturation process? Both positives and negatives
- lees help protect wine from oxygen
- helps maintain slow, controlled oxidation during maturation
- lowers need to use SO2 during this time
- if layer of lees is too thick, can produce VOLATILE, REDUCTIVE SULFUR COMPOUNDS
- some of these compounds can add complexity (struck match, smoke)
- some can give unpleasant aromas (rotten eggs - comes from high levels of hydrogen sulphide (aka reduction))
- provide nutrients for microbes so can assist growth of lactic acid bacteria for MLC but can also encourage development of spoilage microbes (Brett)
39
Describe the process of 'racking' (6)
- process of transferring wine from one vessel to another with aim of removing sediment from wine
- sediment may be gross lees, fine lees, other solid material (tartrate crystals eg)
- wine removed from original vessel through valve near bottom of vessel (but above layer of sediment) and pumped/poured into top of new, clean vessel
- can be oxidative
- can reduce oxygen contact by using pressure from inert gas to push wine out through hose into new vessel which has also been flushed with inert gas
- can be done several times during maturation
40
What does the term 'blending' refer to?
- refers to mixing together of two or more batches of wine
41
When does blending typically take place?
- can take place at any time during the winemaking process but most often carried out just prior to finishing and packaging
42
What is the process involved in blending wine?
- carry out blending trieds using small volumes of wine to distinguish proportion of each wine in favoured blend before doing large scale blend
- requires high level of skill and experience
- can be difficult - especially if you plan on ageing a wine for long period of time so need to estimate how will develop in future
- needs to be carried out before stabilisation in case any instabilities arise from the blend
43
Blending involves combining wine from different...(6)
- grape varieties
- locations (vineyards, regions, countries)
- grape growers/businesses
- vintages
- grapes treated differently in the winery (free run juice, press juice, wines matured in oak, wines matured in stainless steel)
- wines treated the same in the winery but are in different vessels for logistical reasons
44
What impact does legislation have on blending?
- what can and cannot be blended and in what proportions depends on local legislation
e. g. PDO, Chianti Classico DOCG, Brunello di Montalcino DOCG etc
45
Blending: what is the legislation regarding wines labelled 'PDO"
100% must come from defined geographical area
46
Blending: what is the legislation regarding wines labelled 'Brunello di Montalcino DOCG'
100% sangiovese
47
Blending: what is the legislation regarding wines labelled 'Chianti Classico DOCG'
85% sangiovese and other specified grape varieties
48
Why would a winemaker opt to blend his wines? (7)
```
Balance
Consistency
Style
Complexity
Minimise faults
Volume
Price
```
49
Blending: Balance
- increase or moderate levels of certain characteristics
- help produce a better balanced wine
- might blend batch of wine from warmer vineyard with one from cooler vineyard to tune acidity levels
- blend different grape varieties to achieve balance (Merlot and Cab etc)
50
Blending: Consistency
- ensure consistency within volume products
| - some products need consistency across different years (non-vintage champagne, sherry)
51
Blending: style
- fundamental in reaching desired style
- winemakers want to promote their 'house style' or create wine within certain quality level within their range
- some rose made by blending red and white wine and allows for control over colour and flavour profile
52
Blending: Complexity
- blending of two or more parcels of wine which give greater range of flavours
- enhances complexity and quality of final wine
53
Blending: minimise faults
- can reduce presences of wine faults
- e.g. if one barrel showing volatile acidity, can sterile-filter wine to remove acetic acid bacteria and blend into larger volume of un-faulty wine to lower concentration and perception of acetic acid
54
Blending: volume
- small vineyard holdings
- need to blend wines from different vineyards to produce volumes of certain wines
- poor vintages or small vineyard holdings might need to boost amounts to satisfy customers
55
Blending: price
- wines need to be sold to make profite so blending parcels can help create certain style and quality
- e.g. can blend Chardonnay with Semillon and Trebbiano to keep volume the same but the price low as S and T are cheaper than Chardonnay and presence of Chardonnay on label helps it sell
56
Why would a winemaker choose NOT to blend?
Single Vineyard
- maintain fruit character and quality from one vineyard so don't want to blend and ruin this
- 'single vineyard' can make it seem rarer and of higher quality (and pricier)
Dilution
- blending can dilute fresh fruit aromas and distinct characteristics of grapes
WSET 4
flashcards
Decks in class (17)
# Cards
-
D1: The Vine80
-
D2 & D3: The Vine Growth Cycle and The Growing Environment122
-
D4: Approaches to Grape Growing30
-
D5: Vineyard Establishment21
-
D6: Managing Nutrients and Water31
-
D7: Canopy Management38
-
D8: Hazards, Pests and Diseases105
-
D9: Harvest14
-
D11: Wine Components64
-
D12: Approaches to Winemaking18
-
D13: General Winemaking Options84
-
D14: Maturation56
-
D15: Finishing and Packaging99
-
D16: White Winemaking48
-
D17: Wines with Residual Sugar22
-
D18: Red Wine Making55
-
D19: Rose Winemaking15
