Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

WSET 4 > D16: White Winemaking > Flashcards

D16: White Winemaking Flashcards

You may prefer our related Brainscape-certified flashcards:
WSET ® Level 1 Wine flashcards WSET ® Level 2 Wine flashcards WSET ® Level 3 Wine flashcards WSET ® Level 2 Spirits flashcards WSET ® Level 1 Spirits flashcards WSET ® Level 3 Spirits flashcards WSET® Level 4 Wine flashcards
1
Q

Why would you leave grapes in contact with the skin during white wine making?

A

enhance extraction of aroma and flavour compounds and precursors

enhance texture of wine by extracting small amount of tannin

*** carried out on crushed white grapes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why would you NOT carry out skin contact during white wine making?

A

”- doesn’t suit all styles of wine

  • can make wine seem coarse or bitter to taste
  • most have zero or minimal skin contact
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the process for skin contact in white wine making?

A
  • grapes crushed and pressed
    • whole bunches pressed and not crushed as want aroma and flavour compounds from pulp
  • free run juice is drained off
  • remaining grape mass sent to the press
  • can load whole bunches of uncrushed grapes

** all of this is a winemaker choice

** whole bunches can reduce risk of oxidation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why would a winemaker want minimal skin contact?

A
  • want fruit flavours, minimal colour and smooth mouthfeel
  • for early drinking wines (tannins wouldn’t have time to soften)
  • if fruit is under-ripe (would extract bitter flavours and astringent tannins if did have contact)
  • slow process requiring additional equipment and labour
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the benefits of skin contact?

A
  • maximises flavour extraction

- good for aromatic varieties with lots of aroma compounds to be extracted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What varieties benefit from skin contact?

A
  • Riesling
  • Gewurztraminer
  • Viognier
  • Muscat
  • Sauvignon Blanc

(helps give these wines texture as they often aren’t matured in oak)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the negatives of skin contact?

A
  • homogenisation

- can reduce variations between grape varieties and different vineyard sites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How long does skin contact take?

A
  • ranges from an hour to 24 hours

- greater length of time on skins leads to greater extraction of flavour and tannins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What impact does temperature have on skin contact?

A
  • chilling juice reduces rate of extraction and tannins
      • chilled down to below 15 degrees
      • then pressed to separate skins and juice before ferm begins
  • reduces rate of oxidation and microbial spoilage
  • reduces chance of spontaneous fermentation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is orange wine?

A
  • white grapes fermented on skins
    • may undergo post-ferm maceration
  • no temp control or sulfur
  • name comes from colour of wines which develops due to oxidation of compounds extracted from grape skins
  • don’t taste like white wines
  • dry, notable level of tannins
  • nuts and dried fruit
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Grapes are almost always pressed to…

A

separate skins from juice before fermentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Is pressing usually gentle or firm - why?

A

typically gentle pressing to avoid extraction of unwanted compounds from skins and seeds of grape (e.g. tannins and colour)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Destemming?

A
  • important choice

- grapes normally destemmed and crushed before being loaded into the presses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Whole bunch pressing

A
  • reduces chance of oxidation before and during pressing. Can add inert gases to help with this.
  • very gentle form of pressing. Produces juice lower in solids, tannins and colour
  • stems help break up mass of grape skins and provide channels for juice to drain
  • only an option of grapes are HAND-HARVESTED
  • grapes take up a lot of room in the press so fewer grapes can be loaded into each press cycle

** only suitable for small batch prem wines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Free run juice

A
  • grapes drained off as soon as grapes are crushed
  • FREE RUN JUICE
    • can make wine only from this
    • reduces final volume of wine so has cost implication
  • juice which is LOWEST in:
  • SOLIDS
  • tannin
  • colour
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Press Juice

A
  • juice that runs off through pressing
  • has lower acidity and less sugar than FRJ (similar to free run juice but as pressing continues, more solids, tannins and colour are extracted)
  • wines are fuller bodied
  • Can separate into press fractions
    • can be blended later in winemaking and maturation process
    • later fractions likely to be too astringent or bitter (from PHENONLIC COMPOUNDS in skin, seeds or stems)
  • likely to be discarded
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is hyperoxidation?

A
  • technique of deliberately exposing the must to large quantities of oxygen before fermentation
  • targets compounds in the must that oxidise most readily
  • as they oxidise, compounds turn brown
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the aim of hyperoxidation during fermentation?

A
  • compounds precipitate
  • wine returns to normal colour
  • produce wine which is more stable against oxidation after fermentation
  • helps remove bitter compounds from unripe grape skins, seeds and stems
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the risk of hyperoxidation?

A
  • can destroy some volatile aroma compounds found in must and is typically suited to neutral grapes (e.g. chardonnay)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Give an example of hyperoxidation

A
  • reduces levels of volatile THIOLS and METHOXYPYRAZINES in Sauvignon Blanc
  • would not do hyperoxidation if an aromatic fruity or herbaceous style of wine was desired
21
Q

What are the costs associated with hyperoxidation?

A
  • equipment needed isn’t expensive

- it is an extra step in winemaking process which requires labour to set up and monitor

22
Q

When does clarification of the must take place?

A
  • between PRESSING and FERMENTATION
23
Q

What does clarification achieve?

A
  • reduce amount of suspended solids in the must

Solids:

  • skin
  • stems
  • seeds
24
Q

what percentage of solids do you aim for in the must?

A

0.5 - 2%

25
Q

Wines with higher levels of solids…

A
  • some winemakers want higher levels so may not clarify at all
  • want more texture in wine, a subtle astringency
  • can get more aromas during fermentation which add complexity

EXAMPLE: suitable for prem chardonnay

  • needs careful monitoring and management
  • high levels can give REDUCTIVE SULFUR COMPOUNDS which will produce off-flavours
  • only suitable for small prem production
26
Q

Low levels of solid in the must…

A
  • better for fruity aromas

- provides nutrient for yeast

27
Q

Over-clarification can result in…

A

stuck fermentation

28
Q

What are the four methods of clarification?

A

Sedimentation

Flotation

Centrifugation

Clarifying Agents

29
Q

Clarification: Sedimentation

A
  • simplest form
  • AKA ‘settling’
  • cheapest method as requires no extra equipment or additives
  • takes most time so increased pressure on labour and time
  • mainly used for small volume prem production

1) suspended solids in must fall over time with gravity
2) must is chilled to approx 4 degrees (reducing rate of oxidation and microbial spoilage, also avoids spontaneous fermentation)

3) rate depends on size and shape of vessel ( Large, tall vessels: longer process
- Smaller, short vessels: shorter process )

4) takes between 12 and 24 hours

5) clear juice transferred to fermentation vessel, leaving sediment of solids at bottle of sedimentation vessel
- aka: RACKING

  • solids left behind will often be filtered by cross-flow or depth filters to extract extra juice
  • used to clarify wine as well as must
30
Q

Clarification: Flotation

A
  • process of BUBBLING GAS up through the must
  • as bubbles of gas rise, they bring up solid particles
  • particles then skimmed off top of vessel
  • speeds up rate of clarification
  • inert gas used (normally nitrogen)
  • fining agents must be added to must for technique to be successful as helps bind particles together
  • can only be used on must and NOT wine
  • little bit more expensive than sedimentation due to equipment needed but is quick and effective
  • can be used in continuous or batch process
  • requires:
    • gases
    • fining agents
    • equipment for bubbling gas through the liquid
  • must does not need to be chilled so save on energy costs
31
Q

Clarification: Centrifugation

A
  • machine that comprises a rapidly rotating container
  • uses centrifugal force to separate solids from liquids
  • used continuously (rather than as a batch process) so saves time and labour costs
  • expensive to buy so only used in wineries processing large volumes of must quickly
  • increase oxygen exposure to must unless machine is flushed with inert gases so has implication on costs
  • can be used on wine as well as must
32
Q

Clarification: Clarifying Agents

A
  • number of different compounds can be added to the must as processing aids to speed up rate of sedimentation
  • EXAMPLE: PECTOLYTIC ENZYMES break down pectins in must (can only work on must and NOT wine)
  • Some fining agents can aid clarification of both must and wine
  • cost in purchasing agents but may be justified against time and energy save compared to sedimentation
33
Q

What are pectolytic enzymes?

A
  • clarifying agent used in the clarification process of white wine making
  • pectins naturally found in plant cell walls
  • breaking down pectin allows for rapid separation between liquid juice and solids
34
Q

What temperature would you ferment at if you wanted a less-fruity style of wine and might want to use some oak?

A
  • warmer temp
  • 17 to 23 degrees
  • promotes yeast health
  • avoid production of certain esters - ISOAMYL ACETATE
35
Q

What temperature would you choose if you want to protect volatile aromas and flavour compounds?

A

15 degrees

36
Q

Fermenting in stainless steel

A
  • popular for fruity, floral white wines
  • can control temps

EXAMPLES:

  • Sauvignon Blanc
  • Veneto Pinot Grigio
37
Q

Fermenting in concrete/old vats

A
  • good for fermenting at slightly warmer temps

EXAMPLES:

  • Chablis
  • white Rioja
38
Q

Fermenting in small oak barrels

A
  • good for some prem and super-prem chardonnay
  • monitoring can be a bit labour intensive rather than just using one large vessel
  • wines tend to have deeper colour and fuller body (oxidative environment; more oak-derived aromas due to yeast activity during fermentation)
  • increased contact between wine and yeast lees which gives more texture
  • give more blending options as wine in each barrel will be different after fermentation process
39
Q

What are the effects of MLC on White Wines?

A
  • reduction in acidity (increasing pH of wine)
  • increase in microbiological stability
  • modification to flavours of wine
40
Q

What is the effect of MLC on low-aromatic varieties?

A

choice between:

  • perceived greater complexity of wines that have been through MLC
  • primary fruit characters of those which havent
41
Q

What is the effect of MLC on aromatic varieties?

A
  • avoided so as to preserve primary aromatics, even though they are high-acid wines
  • preserve individual varieties
42
Q

What adjustments can MLC make to the wine?

A
  • can adjust acidity at this stage

- can reduce alcohol of wine at this stage

43
Q

What maturation are prem and super prem wines likely to go through?

A
  • Prem and super-prem wines made from low-aromatic varieties likely to be aged in small oak barrels to increase texture and complexity of flavour
  • aromatic varieties would not
44
Q

What maturation process are inexpensive wines likely to go through?

A
  • likely to be too costly so get oak influences through other oak alternatives
45
Q

What are the aims of lees ageing in white winemaking? (5)

A
  • give body
  • soften mouthfeel
  • helps stabilize wine
  • protect wine from oxygen
  • may introduce some reductive sulfur compounds
    • at low levels can be desirable (struck match, smoke)
46
Q

What is batonnage?

A
  • stirring the lees from bottom of vessel and mixing with wine
  • optional
  • increases release of yeast compounds in wine
  • use rod and manually stir lees in wine
  • increases oxygen exposure as have to remove bung from vessel
  • can result in an increase in effects from dead yeast and decrease in fruity flavours
  • can lead to development of reductive sulfur compounds and off-aromas so needs v careful management
47
Q

What is an alternative option to batonnage?

A

BARREL RACKS

  • can easily roll the barrels to agitate the lees
  • doesn’t involve opening vessel
48
Q

Cost of lees agegin

A
  • very costly to do this on a number of vessels so only likely for prem and super-prem production

WSET 4 (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions