Brainscape's Knowledge GenomeTM

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


See full index

dipWSET D1 | Production of Wine > L3C07 Common Elements In Winemaking And Maturation > Flashcards

L3C07 Common Elements In Winemaking And Maturation 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 Wine Appreciation flashcards Introductory Sommelier Exam (CMS) flashcards WSET ® Level 3 Spirits flashcards WSET® Level 4 Wine flashcards
1
Q

What is the next stage in winemaking after harvest?

A

The grapes are processed and prepared for alcoholic fermentation

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

On a basic level, what is alcoholic fermentation?

A

Yeast converts sugars in the grape to alcohol

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

What is the next basic stage of winemaking after alcoholic fermentation?

A

The wine needs to be stored prior to packaging and sale

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

Broadly speaking, what are natural wines?

A

Wines made with minimal intervention

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

Describe the seeds and stems of the grape

A

Both contain tannins

Seeds contain high levels of bitter oils

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

How are stems made available to the winemaker

A

By hand harvesting

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

Why is the grape skin important to the winemaker?

A

The skin and the area immediately underneath, contain high levels of flavour compounds (containing the grape’s signature character)
It contains tannins
It contains colour compounds

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

A large number of chemical compounds are classed as…

A

Tannin

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

Describe tannins at Véraison

How does this change?

A

They taste very bitter and astringent

As grapes ripen, bitterness and astringency fall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the Bloom of a grape?

A

The waxy surface that covers the skin of a grape

It contains yeast that can be used for fermentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

List the three major constituents of a grape’s pulp

A

Water
Sugar
Acid

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

What is the largest constituent of a grape’s pulp?

A

Water

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

What is the second largest constituent of a grape’s pulp?

A

Sugar

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

In order, what are the most abundant acids in a grape’s pulp?

A

Tartaric acid

Malic acid

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

What can oxygen react with during winemaking and maturation?

A

Grape juice

Many of the component parts of a wine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is oxidation?

A

Oxygen reacting with any component part of a wine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the biggest threat to a winemaker wanting their wine to be dominated by primary fruit characteristics?

A

Oxidation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is the risk of oxidation broadly avoided by a winemaker?

A

Use of antioxidants such as Sulfur Dioxide

Keeping oxygen contact to a minimum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why might grapes be picked at night?

A

It is cooler and the effect of oxygen is reduced because chemical reactions occur more slowly at lower temperatures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How are grapes kept away from oxygen once they reach the winery? What is this process called?

A

By filling airtight winery equipment with carbon dioxide or nitrogen before they are used for grape processing or winemaking
Protective/anaerobic winemaking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the argument against anaerobic winemaking?

A

Some argue that the resultant wines may be bland or uninteresting and that a higher level of oxygen contact helps to develop complexity and character

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

…rarely if ever benefit from oxygen contact during maturation

A

Wines that have been protected from oxygen during winemaking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How are anaerobically made wines stored?

A

In inert airtight vessels which are kept completely full

The vats are made from stainless steel or cement lined with epoxy-resin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How are aerobically made wines usually stored?

A

In wooden vessels that are normally made of oak

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Oak is…but it is not…

A

Watertight

Airtight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How does the mild oxygen permeability of oak help a wine?

A

It can help to soften tannins in red wines

Gives more flavour complexity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What happens to flavours in wine during deliberate oxidation/maturation?

A

Primary fruit flavours gradually fade

Tertiary characters start to develop, such as leather and earth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Other than flavour, how may a wine change as a result of oxidation?

A

Red wines become paler and gain a hint of brown

White wines become deeper in colour and gain a hint of orange

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What two main factors influence the amount of deliberate oxidation a wine receives?

A

Size of vessel

Length of time stored in it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How does barrel size affect the amount of oxidation a wine receives? Why?

A

Smaller barrels have a greater oxidative effect

They present a proportionately larger surface area of wood to the wine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How large is a barrique?

A

225L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Wines are rarely kept in barriques for longer than…

A

Two years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How may the effect of barrel oxidation be further enhanced?

A

If the container is not completely full

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Name three wines which are matured in barrels which are not completely full

A

Oloroso Sherry
Rutherglen Muscat
Tawny Port

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What characters do wines which are deliberately aged take on?

A

Caramel, toffee and nuts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What may happen to a wine if it’s exposed to too much oxygen?

A

It can lose much of its fruit flavour and smell stale

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What can happen to over-oxidised wine in extreme cases?

A

Bacteria can use the oxygen to turn the wine to vinegar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the main uses of Sulfur Dioxide in a winery?

A

Antioxidant effects

Antiseptic effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Which element in winemaking can be toxic? How is this prevented?

A

Sulfur Dioxide

It is regulated by law

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Which major element in winemaking can cause allergic reactions, even at low levels?

A

Sulfur Dioxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Why might a quality-conscious winemaker want to keep SO2 levels as low as possible?

A

It can make wines seem harsh and lacking in fruit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

When used as an antioxidant, why must SO2 levels be constantly monitored?

A

By protecting wine from oxidation, SO2 becomes ‘bound’ and can have no further protective use

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Why is SO2 effective as an antioxidant?

A

It is toxic to the many strains of yeast and bacteria that can cause unwanted flavours in wine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Is SO2 toxic to the principal fermentative yeast involved in winemaking?

A

No, this strain is resistant to certain levels of SO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

The majority of wooden vessels used in winemaking are made of…

A

Oak

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Other than oxygen, what can oak ageing give to a wine?

A

Tannins

Flavours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What does oak-tannin give to a wine?

A

Structure/textural complexity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What kind of flavours can oak give to a wine?

A

Toast
Vanilla
Smoke
Cloves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What is a particular challenge when using oak for maturation? Why?

A

Hygiene

It is particularly difficult to keep wooden vessels free of yeasts, bacteria and moulds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Why may a winemaker use different types of vessel during maturation?

A

As oak vessels differ widely in their characteristics

To enhance complexity in their wines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What are the four major factors to consider when choosing oak for maturation?

A

Species and origin of oak
Size
Production of oak barrels
Age

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Describe why species of oak is an important factor in flavour characteristics

A

Flavour can change, even within a species of oak

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

…oak has broadly similar characteristics no matter which country it’s from

A

European

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Where is some of the finest oak considered to be from?

A

Some forests in France

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is a 228L barrel known as?

A

Pièce

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

How large can wine maturation vessels get?

A

More than 2000L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What is one of the most important procedures when it comes to how a barrel affects the flavour of a wine?

A

Toasting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

How are the barrel’s staves prepared so they can be bent into shape?

A

They are heated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What secondary effects does the heating of a barrel’s staves have?

A

It transforms the tannins and the flavour compounds in oak

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What flavours are newly produced by a barrel once it is toasted?

A

Sweet spice

Toast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What does ‘level of toasting’ refer to in the making of a barrel?

A

The temperature and length of heat exposure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What affects the flavours a barrel can give to a wine?

A

The level of toasting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What happens each time a barrel is used?

A

The effect of toasting diminishes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Why might a winemaker not use new oak?

A

In order to make a wine with subtler oak flavours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

How else may oak flavours and tannins be added to a wine, other than using barrels? What is the advantage of doing this?

A

By using oak staves or oak chips

It’s cheaper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

How may the oxidative effects of barrel ageing be replicated?

A

By adding small, controlled quantities of oxygen to the wine vessel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What is an inert wine vessel?

A

It does not add flavour to the wine or allow oxidation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What are the majority of inert winery vessels made from?

A

Stainless steel or concrete

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What can inert winery vessels be used for?

A

Fermentation

Temporary storage of wine after it is finished

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What are most modern winery vessels made from?

A

Stainless steel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

List the advantages of stainless steel as a winery vessel

A

Easy to keep clean
Can be made into any shape and size
Can incorporate temperature control mechanisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What are the two main types of temperature control mechanisms?

A

Sleeves on the outside of the vessels

Internal coils through which cold or hot liquid can be circulated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What are concrete vessels usually lined with? What does this do?

A

Epoxy resin

It’s inert and provides a waterproof barrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What was commonly used before stainless steel vessels?

A

Concrete vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What are the disadvantages of concrete vessels over stainless steel?

A

They can be less easy to clean and maintain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Why might some winemakers prefer concrete vessels?

A

The thick concrete shells help to regulate temperature during fermentation and maturation without the need for expensive equipment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

Name a wine vessel which is not steel or concrete…

A

Glass bottles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

When do grapes usually use their first dose of SO2?

A

When they arrive at the winery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

Besides receiving SO2, what else may happen to wine grapes during reception?

A

They may be individually checked and sorted for unripe and rotten grapes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

What is the next possible stage after grape reception?

A

Destemming and crushing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

What does crushing do?

A

It breaks the skin of the grapes and liberates a quantity of juice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

What is the liquid product of crushing called?

A

Free run juice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

What is the danger when crushing grapes?

A

If the seeds are crushed, they will release bitter oils and tannin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

What does pressing do?

A

It separates the liquid and solid constituents of the grape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

Why are modern pressing techniques designed to be gentle?

A

As with crushing, to avoid crushing the seeds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

What is the traditional design of grape presses?

A

They were all vertical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

How does a vertical press work? What is a traditional vertical press called?

A

The pressure on the grapes comes from above, using a screw or lever
A basket press

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

Name a wine producing region which is still particularly known for its vertical presses

A

Champagne

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

Describe a pneumatic press

A

An inflatable rubber tube within a perforated, horizontal stainless steel cylinder

90
Q

What does a pneumatic press allow that a vertical press does not?

A

It’s possible to apply pressure over a larger area in a controllable way

91
Q

Why are some presses built within a closed tank?

A

So that the amount of oxygen in contact with the juice is kept to a minimum

92
Q

What is it important to be aware of regarding the juice which is pressed?

A

Liquid released at the start of pressing is very different to liquid released at the end

93
Q

What are fractions?

A

Different pressings of grape juice/wine

94
Q

What may be done with different ‘fractions’?

A

They may treated individually and blended in different proportions to create a certain style

95
Q

When may adjustments take place?

A

Before, during or after fermentation

96
Q

How is grape juice commonly referred to?

A

Must

97
Q

What is the term for the level of sugar in grape juice?

A

Must weight

98
Q

How may sugar be increased in a wine? What is it called?

A

By adding Rectified Concentrated Grape Must

Enrichment

99
Q

What is Rectified Concentrated Grape Must?

A

A colourless, odourless, syrupy liquid

100
Q

At what stage may a must be enriched?

A

Before or during fermentation

101
Q

Which wine adjustment is banned in many parts of the world?

A

Enrichment

102
Q

What may happen to a wine if the process of enrichment is abused?

A

It may become hard and thin

Because there are insufficient flavours to balance the artificially elevated alcohol

103
Q

What is chaptalisation?

A

Where sugar from sources other than grapes is added as a form of enrichment

104
Q

Other than enrichment, how else may alcohol levels be raised in a must/wine?

A

By removing water from the must

105
Q

What are the disadvantages of removing water to concentrate sugar/alcohol?

A

As well as sugar, it concentrates tannins, acids, flavour compounds and faults
It reduces volume too

106
Q

Name an adjustment which is very difficult

A

Removing sugar

107
Q

Can alcohol be removed from wine?

A

Yes, after fermentation is complete

108
Q

How is acid usually increased in a wine?

A

By the addition of tartaric acid in powder form

109
Q

Where is acidification permitted?

A

In Europe, only in warmer countries

In many hot countries around the world

110
Q

How may a wine be de-acidified?

A

By the addition of an alkali

111
Q

What are the inputs and outputs of fermentation?

A

Sugar and yeast

Alcohol and CO2

112
Q

What are the ‘other’ by-products of fermentation?

A

Heat and flavour compounds

113
Q

Which yeast species is responsible for the majority of wine fermentations? Why is this used?

A

Saccharomyces cerevisiae

Due to its tolerance of relatively high alcohol levels and SO2

114
Q

What is the minimum temperature at which fermentation can begin?

A

5C

115
Q

At what point does fermentation naturally stop?

A

When all the sugar has been consumed

116
Q

What may stop fermentation before all sugar has been consumed?

A

Yeast run out of nutrients
Temperature reaches over 35C
Combination of high sugar and alcohol

117
Q

What may happen to fermentation if sugar levels are very high?

A

Fermentation may not even start

118
Q

Broadly speaking, how may a winemaker deliberately halt fermentation?

A

By killing yeast

By removing yeast

119
Q

How may yeast be killed?

A

Adding SO2

Adding grape spirit

120
Q

Describe how a winemaker may remove yeast?

A

By temporarily halting fermentation, by chilling the must to below 5C
By filtering the yeast out

121
Q

What are the two important ways in which a winemaker may control fermentation?

A

Choice of yeast

Temperature management

122
Q

What are the two yeast choices a winemaker has?

A

Whether to use the ambient yeast strains on the grape bloom, or adding cultured strains to the must

123
Q

What is the advantage of using ambient yeast strains?

A

It can produce complex flavours in the final wine

124
Q

What is the disadvantage of using ambient yeast strains?

A

The winemaker cannot control exactly which yeast strains are present
There may be some variation between batches of grapes

125
Q

What are commercially available yeasts?

A

Strains of S. Cerevisiae that have been specifically selected because they consistently perform and produce attractive flavours

126
Q

What is a potential argument against using cultured yeasts?

A

That it can limit the potential complexity of the wine

127
Q

Why is temperature management important in the winery?

A

Because if fermenting wine becomes too hot, yeast are killed

By controlling temperature, the winemaker can influence the wine’s flavours

128
Q

What is achieved by fermenting at lower temperatures?

A

It avoids the loss of most volatile aromas (which often have a floral character)
It can encourage the development of fruity aromas in white wines

129
Q

What is achieved by fermenting at higher temperatures?

A

This is necessary for the extraction of colour and tannins from black grape skins

130
Q

Why is temperature control during fermentation easier now than it was?

A

Many vats have their own heating/refrigeration systems

131
Q

Other than automatically, how may excess heat be releases during fermentation?

A

By pumping over

132
Q

Name a winemaking technique which has been pivotal in quality and consistency of modern winemaking

A

Precise temperature control

133
Q

When does malolactic fermentation usually take place?

A

Once alcoholic fermentation has finished

134
Q

What carries out MLF?

A

Lactic acid bacteria

135
Q

What happens during MLF?

A

Lactic acid bacteria convert tart malic grape acid into softer lactic acid

136
Q

What does MLF broadly do?

A

Softens and reduces acidity
Creates buttery flavours
Produces CO2

137
Q

How may MLF be encouraged??

A

By raising the temperature of the wine and not adding SO2

138
Q

How may MLF be avoided?

A

Through storage at cool temperatures
Use of SO2
By filtering out the bacteria

139
Q

Why may wine appear cloudy after fermentation? What becomes of this effect?

A

Due to the presence of dead yeast cells and grape fragments

The offending particles are usually heavy enough to fall to the bottom of the vessel within a few hours

140
Q

What is the sediment that falls to the bottom of the vessel after fermentation?

A

Gross lees

141
Q

What is the result of gross lees are not removed?

A

Unpleasant aromas can develop in the wine

142
Q

What are fine lees?

A

Smaller particles in the wine after fermentation (which settle more slowly)

143
Q

How are fine lees removed?

A

They are removed gradually during the wine maturation process

144
Q

Why may a winemaker not want to remove the fine lees during pre-bottle maturation?

A

To add extra flavours and a richer texture to the wine

145
Q

Why may a wine be bottled after only a few months?

A

The winemaker may want to preserve as many primary fruit aromas as possible

146
Q

Give an example of a premium wine which is only matured for a short time, in inert vessels before bottling

A

Premium Australian Riesling

147
Q

What is the most important factor in determining how well a wine will survive medium to long-term ageing?

A

It needs to have flavours that will develop in an interesting way

148
Q

What changes can occur during pre-bottling maturation?

A

The vessel can affect the wine’s flavours by adding oak flavours or allowing the wine to oxidise
Over time, wine components can react with each other, altering flavour or balance (and sometimes creating sediment in the vessel, which is periodically removed)

149
Q

When does blending take place?

A

It can take place at any stage during winemaking

150
Q

When does blending usually take place?

A

After fermentation or during maturation

151
Q

What is blending used to achieve?

A

Improve balance
Attain consistency
Achieve a certain style

152
Q

What may impede blending?

A

Local laws

153
Q

Give an example of when blending may be used to improve balance

A

When making red wine, free run wine may be blended with press wine to increase tannins in the final product

154
Q

Give an example of when blending may be used to achieve consistency

A

Wines matured in small barrels can develop in subtly different ways and may be blended together in a large vat to smooth out inconsistencies
Variations may arise due to differences in fruit (harvested at different times)
Inconsistencies may arise during winemaking

155
Q

How may a winemaker go about achieving their ‘house style’

A

By creating as many blending options as possible during the winemaking process

156
Q

List some variations of blends that a winemaker may create

A

Separating press fractions
Fermenting/maturing in different vessels
Allowing only a proportion to go through MLF
Using different grape varieties
Different vineyard plots
Different vintages

157
Q

What are the three main techniques a winemaker may use to clarify a wine?

A

Sedimentation
Fining
Filtration

158
Q

Why may a wine not go through all clarification treatments?

A

Because some winemakers believe that some of the treatments may harm the character of the wine

159
Q

What is racking?

A

Once the gross lees have settled in a deposit, the wine is gently pumped into another vessel, leaving the sediment behind

160
Q

How are fine lees dealt with after racking?

A

Racking may be repeated several times during maturation

161
Q

For some wines,…is the only clarification that will take place

A

Sedimentation and Racking

162
Q

What is the major disadvantage of natural sedimentation as a means of clarification?

A

It is very slow

163
Q

How may sedimentation be accelerated? What is the disadvantage of this?

A

By putting wine in a centrifuge

The equipment is very expensive

164
Q

What is fining?

A

It speeds up the process of deposits clumping together in a wine so that they can be removed

165
Q

How is fining performed?

A

By adding a fining agent to the wine and removing the clumps that appear

166
Q

Why may a winemaker not add a fining agent to a wine

A

Some winemakers believe it can adversely affect flavour and texture

167
Q

What is filtration?

A

A process that physically removes particles from a wine as it is passed through a filter

168
Q

When may filtration be performed?

A

After fermentation, during maturation and before bottling

169
Q

What are the two methods of filtration?

A

Depth filtration

Surface filtration

170
Q

Describe the filters in depth filtration

A

They are made from a thick layer of material

171
Q

Describe depth filtration

A

As wine passes through the filter, the solid parts become trapped inside it

172
Q

What can depth filtration achieve?

A

It can handle very cloudy wines and remove gross lees

173
Q

Describe filters in surface filtration

A

They resemble very fine sieves

174
Q

How does surface filtration work?

A

Solid particles are trapped on the surface of the filter as wine passes through

175
Q

What are the disadvantages of surface filtration?

A

Filters are very expensive

Filters clog very easily

176
Q

How is the expense of surface filtration minimised?

A

By only using it after depth filtration

177
Q

What is sterile filtration?

A

Where the pores in a surface filter are small enough to remove yeast cells and bacteria

178
Q

When may sterile filtration be performed?

A

Just before bottling

179
Q

Why are some bottles unfiltered?

A

Some winemakers believe that filtration can negatively affect a wine’s character, especially its texture

180
Q

When is a wine considered stable? Why does this vary?

A

If over a specific time, it changes in a slow, predictable manner
The rate and amount of change deemed acceptable will vary from wine to wine

181
Q

Name a stabilisation process and explain why it is considered to ‘stabilise’

A

Fining

It aims to produce a predictable outcome after bottling

182
Q

Other than fining, name three other important areas that require stabilisation

A

Tartrate stability
Microbiological stability
Oxygen stability

183
Q

Why can tartaric acid crystals form in wine? What are they called?

A

Tartaric acid is less soluble in wine than in grape juice

Tartrates

184
Q

What do Tartrates look like?

A

Clear crystals in white wine

Purple crystals in red wine (stained by colour compounds)

185
Q

What is the big disadvantage of Tartrates?

A

They spoil the appearance of the wine

186
Q

How is the formation of Tartrates accelerated?

A

In cool temperatures

187
Q

How may a winemaker force tartrate formation?

A

By chilling the wine to below 0C

188
Q

How are tartrate crystals removed?

A

Filtration

189
Q

Why are yeast and bacteria undesirable in wines?

A

They can spoil a wine and make it undrinkable

190
Q

Why is it important to keep equipment sterile from a microbiological perspective?

A

Undesirable microorganisms can thrive in grape and wine residues

191
Q

Which wines may not be at risk from microorganisms?

A

Fortified wines

Their alcohol levels are toxic for all microorganisms

192
Q

Name a non-fortified wine which is highly resistant to microbiological spoilage

A

A dry, high-acid wine that has undergone MLF

193
Q

Which wines are most prone to microbiological spoilage?

A

Low acid, low alcohol wines, which have not undergone MLF and have a little residual sugar

194
Q

How are more susceptible wines treated to prevent spoilage?

A

With SO2

Sterile filtration

195
Q

How may oxidation risk be reduced in a wine?

A

Minimising oxygen contact

Keeping SO2 topped up

196
Q

Name an extra measure a winemaker may take during packaging to minimise oxidation risk

A

The bottle may be flushed with CO2 or nitrogen before filling to eliminate oxygen

197
Q

What are the advantages of glass bottles?

A 
Portable
Cheap
Quite strong
Oxygen impermeable
Do not impart flavours to wine
198
Q

What are the main disadvantages of glass bottles? Explain this

A

They are heavy and rigid
Weight adds to transport costs
Rigidity means it cannot be packed to make best use of the available space

199
Q

How are the disadvantages of glass bottles being counteracted?

A

Some producers are using lighter bottles

Some bottle in or closer to the destination country

200
Q

Apart from logistics, why is bottle rigidity a disadvantage?

A

It means that when half-full, the bottle will contain a space for air

201
Q

What is the main disadvantage of plastic bottles for wine?

A

They are slightly oxygen permeable and wines may lose their freshness within a matter of months

202
Q

What is the advantage of bag-in-box wines?

What is the disadvantage?

A

The bag collapses as wine is drunk, preventing air from entering
The plastic bag is still oxygen permeable

203
Q

Within what time period must a bag-in-box wine be consumed?

A

18 months

204
Q

What factors may dictate the type of closure which is used for a bottle?

A

Ease of use
Which closures a bottling line is designed to use
For bottles intended for maturation, it must allow the wine to mature positively

205
Q

What does a slow release of oxygen allow in some wines?

A

The development of tertiary flavours

206
Q

What does an airtight closure allow?

A

Retention of fresh fruit flavours

207
Q

Why may a winemaker not be able to choose their bottle closure?

A

It may be overridden by the preference of the consumer market

208
Q

What is the most widely used bottle closure?

A

Cork

209
Q

What is the major benefit of cork as a wine closure?

A

It allows very small amounts of oxygen to enter the wine, thus allowing the development of sometimes desired tertiary flavours

210
Q

What are the two problems with cork-closed wines?

A

The risk of cork-taint

Risk of oxidation

211
Q

What causes cork taint?

A

Trichloroanisole (TCA)

212
Q

What effect does TCA have on a wine?

A

Gives wine a mouldy, cardboard-like aroma

213
Q

How are winemakers battling the risk of TCA?

A

By investing large sums in treatments designed to prevent its formation

214
Q

Hat are synthetic corks made from?

A

A form of plastic

215
Q

What is the disadvantage of synthetic corks as closures?

A

They are generally designed for wines intended for early consumption

216
Q

Who has championed the use of screw caps?

A

Producers from Australia and New Zealand

217
Q

What are the advantages of screw caps as closures?

A

They do not taint wine

They provide an impermeable seal from air

218
Q

What have trials shown about screw caps?

A

They preserve fruit flavour in wine longer than cork

219
Q

How has the disadvantage of screw caps as a closure been countered by some producers?

A

Some screw caps have been designed to have some oxygen permeability

220
Q

Within what time are the majority of wines best consumed?

A

One year

221
Q

What happens to wines not intended for ageing when kept in bottle for more than a year?

A

They lose their primary fruit flavours

222
Q

Give examples of wine styles which can mature in bottle for several years and are no at their best immediately after bottling

A

Vintage Port
The finest German Rieslings
Bordeaux Crus Classés

dipWSET D1 | Production of Wine (38 decks)

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