Vinification Flashcards

1
Q

Which statement about Malolactic Fermentation MLF is false?

The bacteria is sensitive to SO2 and can be stopped by it.
Lowers the perceived acidity in a wine by converting the crisp malo acid to softer lactic acid
Can suppress the varietal purity and can add butter, hazelnut flavours
All white wines and most reds undergo MLF

A

All white wines and most reds undergo MLF

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2
Q

RCGM means?

A

Rectified Concentrated Grape Must and it is used to adjust the residual sugar level in commercial wines.

Because it is a product of wine it is legally allowed in many countries to be added back to a wine.

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3
Q

What are the three ways to make Rosé wine?

Briefly summarise them

A

Direct Pressing - Grapes crushed and pressed (as for white wine) being careful not to press too hard. Fermented cool as for white wine. Used for delicately coloured Rosés

Short Maceration - Grapes crushed and allowed short maceration. Free run juice drained and fermented at low temp as for white wine. Produces darker Rosés.

Blending - Small amount red wine added to white. In EU only permitted in Champagne. Some fruity inexpensive New World Rosés made this way

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4
Q

What is the correct order for typical red wine production?

Crush, press, ferment, maturation, bottling
Crush, ferment, press, bottling, maturation
Crush, ferment, press, maturation, bottling
Crush, Ferment, maturation, press, bottling

A

Crush, ferment, press, maturation, bottling

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5
Q

What is RCGM and what is it used for?

A

RCGM = Rectified Concentrated Grape Must

= Grape must that has had its non-sugar components eliminated.

Used to

  • increase sweetness in the finished wine
  • increase alcoholic potential of wine (chaptalization)
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6
Q

Vinification is defined as:

A

-The process and decisions made by winemakers IN the winery that affect quality and style of wine.

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7
Q

What are the 4 human factors affecting style, quality and price of wines?

A

Grape growing

Winemaking

Maturation

Market forces

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8
Q

What happens if white wine is fermented at too low a temperature?

A

Creation of pear drop aromas and can fail to capture varietal fruit characters

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9
Q

How would you acidify grape juice?

A

Add Tartaric acid

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10
Q

How is acidification normally carried out?

Where is this normally done?

A

By the addition of tartaric acid in powder form.

Common in many warm and hot regions around the world. In Europe, it is only permitted in warmer regions.

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11
Q

List the 3 methods of clarification

A

Sedimentation (Racking)

Fining

Filtration

  • depth filtration
  • surface filtration
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12
Q

Which one of these is not a method used in anerobic winemaking?

Use of SO2 at harvest time
Picking at night when it is cooler
Fermentation in Stainless Steel
The use of specially cultured yeast strains

A

The use of specially cultured yeast strains

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13
Q

A friend opens a bottle of wine and discovers what looks like glass in the bottom of the cork.

What are these, actually?

What is their presence an indicator of?

A

Tartrate crystals.

Indicates that the wine has not been cold-stabalized.

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14
Q

Below ____, yeasts will remain inactive.

Above ____, yeasts will die.

A

50o F

113oF

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15
Q

What is ‘Press Wine’ and what is it used for and what are ‘press fractions’?

A

When maceration has finished, the ‘free run’ wine is drawn off the skins then the remaining mass is pressed creating ‘press wine’.

Early pressings are much the same as the free run wine but with more pressure the ‘free run’ gets progressively darker - press fractions.

Later press fractions may be used to adjust colour and tannin in the final blend.

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16
Q

What happens if white wine is fermented at too high a temperature?

A

Can encourage more complex non fruit aromas to develop BUT risks losing losing varietal fruit aromas.

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17
Q

Which statements about blending are true?

1) Blending of grape varieties is common
2) Blending of vintages is allowed in some regions.
3) Blending can occur at any stage of the winemaking process
4) Blending of different pressing fractions can help balance.

1 only
1 & 2
1, 2 & 4
1, 2, 3, 4

A

1, 2, 3, 4

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18
Q

MLF stands for?

A

Malolactic Fermentation.

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19
Q

What is MLF and what does it achieve?

A

MLF = Malolactic fermentation

Takes place once alcoholic fermentation has finished

Converts tart Malic acid (found in apples) into softer Lactic acids (found in milk).

This softens and reduces acidity, rounds out a wine’s texture and creates buttery (diacetyl) flavours.

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20
Q

Protective wine making is most likely to result in wines that are:

Oaky.
Complex.
Fruity in Style.
Age worthy.

A

Fruity in Style.

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21
Q

Adding an Alkali will?

Increase the acidity in the wine or must
Decrease the acidity in the wine or must
increase the tannins in the wine or must
decrease the tannins in the wine or must

A

Decrease the acidity in the wine or must

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22
Q

How would you de-acidify grape juice?

A

Addition of various alkali

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23
Q

Name and briefly summarise 3 methods of ‘Whole Bunch Fermentation’.

A

Carbonic Maceration - Placing whole uncrushed bunches into vats that are filled with CO2 to remove oxygen. Intracellular Fermentation starts and at 2% ABV the skins split releasing juice. Then usually pressed and yeast then complete fermentation. Method extracts colour but little tannin, wines are soft and fruity with notes of Kirsch, bubblegum and cinnamon like spice.

Semi Carbonic - Similar to Carbonic but vats not filled with CO2. Vats filled with whole bunches, top ones crush bottom releasing juice. Ambient yeast ferments juice which creates CO2, intact berries undergo Carbonic Maceration. Can result better grape aromas.

Whole Bunches with crushed fruit - Whole bunches mixed with crushed grapes, no CO2 but bunches blanket crushed grapes keeping out oxygen so intracellular fermentation takes place.Technique thought to give wine silkier texture and brighter fresher fruit character.

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24
Q

Which one of these is not a sign that a wine has become exposed to too much oxygen?

White wines get darker.
Red wines get lighter.
Wines lose their fresh fruit flavour.
Bacteria will cause the wine to lose acidity, develop buttery flavours and become fizzy.

A

Bacteria will cause the wine to lose acidity, develop buttery flavours and become fizzy.

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25
Q

Sedimentation is?

A

When large particles settle at the bottom of the tank and the wine is decanted off.

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26
Q

Sterile filtration is

1) Not necessary for fortified wines.
2) A surface filter with pore size small enough to remove yeast and bacteria.
3) Is not required for low acid, sweet wines that have not undergone MLF.
4) A filter whose pores can block up easily.

1,2,3 & 4
2, 3 & 4
1, 2 & 4
1, 3

A

1, 2 & 4

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27
Q

List 4 considerations during white wine making

A

Skin contact

Clarification

Fermentation temperature

Choice of vessel

  • Inert
  • Inert (+ Oak)
  • Barrels
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28
Q

What is the purpose of ‘Whole Bunch Fermentation’?

A

The use of whole bunches of uncrushed grapes in the fermentation varying from a small % to the entire vat.

The objective being to create an oxygen free environment for the uncrushed fruit, and to limit skin contact, which imparts tannin and color.

The berries create some alcohol in their cells without yeast referred to as ‘Intracellular Fermentation’.

A range of distinctive fruity aromas is created in the berry which gives wines, made this way, unique qualities.

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29
Q

Give 5 reasons why you might blend wine

A

Balance

Consistency

Style

Complexity

Price

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30
Q

What is ‘Post-fermentation Extraction’?

What is a specific example of a wine/style that utlizes this technique?

A

Maceration after fermentation encourages further extraction of tannin which may or may not be desirable.

Some winemakers believe it results in smoother tannin structure.

Very common with tradional Barolo producers.

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31
Q

Why is sorting grapes an important part of the vinification process?

A
  • Necessary to remove excess leaves, branches, damaged fruit, MOG
  • sorting can be done by hand, either cluster by cluster or by selecting single grapes from clusters
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32
Q

In Sweet winemaking name 6 methods that result in sweeter wine

A

i. Stopping fermentation by Fortification, by adding high dose of SO2 or chilling the fermenting wine (must then be filtered).
ii. Adding a sweetening component such as Süssreserve or RCGM
iii. Using grapes affected by Noble Rot
iv. Drying grapes on the vine (become like raisins) ‘Passerilage’
v. Drying grapes after picking ‘Passito’ (in Italy) delivers ‘Recioto’ wine
vi. Freezing on the vine ‘Eiswein’ or ‘Ice Wine’.

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33
Q

Which of these are reasons that Alcoholic fermentation may stop?

1) The sugar is consumed
2) The temperature is above 35℃
3) The yeast runs out of Nutrients
4) The sugar and alcohol level is too high.

1, 2, 3, 4
1 only
1, 2, 4
1, 2, 3

A

1, 2, 3, 4

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34
Q

List, in order, the minimum steps that must happen to make White Wine

A
  • Grapes pressed and skins extracted (or pressed as whole bunches)
  • Juice clarification
  • Alcoholic fermentation
  • Rack off Gross Lees
  • Newly made wine
  • Packaging and offered for sale
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35
Q

Oxygen during wine making is?

Always positive.

Always negative.

Sometimes positive and sometimes negative.

Has no impact on the final wine.

A

Sometimes positive and sometimes negative

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36
Q

Name 3 tertiary flavours are a result of excess oxidation during maturation?

A

caramel, toffee, nuts

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37
Q

To prevent MLF from occuring, temperature and SO2 levels should be:

A

Temperature: Low

SO2: High

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38
Q

What are necessary elements for a wine to be able to age well?

A

High tannin

High Acidity

High alcohol

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39
Q

Which one of these is NOT a flavour associated with oak barrels?

Cloves
Toast
Leather
Vanilla

A

Leather

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40
Q

Which is not often part of anaerobic wine making?

Maturing wines in old oak barrels.
Use of antioxidants on the grapes during picking.
Picking at night when the temperatures are low.
Filling airtight equipment with Carbon Dioxide or Nitrogen.

A

Maturing wines in old oak barrels.

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41
Q

Which one of these is wrong about using Sulphur dioxide in wine making?

SO2 Levels are limited because it can be toxic at very high levels.

It is an antioxidant

It is used to adjust the acidity of wine.

It’s an antiseptic

A

It is used to adjust the acidity of wine.

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42
Q

Name 3 choices for a white wine maker after fermentation.

A
  1. Mature in oak or inert vessels (with or without Oak staves or chips).
  2. Omit or keep the fine lees to add texture and flavour to the wine.
  3. Allow or block MLF
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43
Q

For premium wines what is the usual fermentation temp range for Cab Sav and why?

A

Generally 79~860F, being warm enough for sufficient extraction yet cool enough to promote fresh fruit flavours.

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44
Q

A Depth filter is?

A

A type of filter that is made up of material such as earth/clay. When the product is passed through the filter, larger particles are caught amongst the material.

45
Q

What is the fermentation temperature range for white wine?

A

53oF~71oF

46
Q

Which wine is not made by leaving a gap at the top of a barrel?

Rutherglen Muscat.
Olorosso Sherry.
Champagne.
Tawny Port.

A

Champagne.

47
Q

Which is not a method for the wine maker to artificially stop the fermentation?

Addition of tartaric acid
Chill the wine and filter.
Addition of SO2
Addition of Spirit to raise the alcohol level .

A

Addition of tartaric acid

48
Q

What does ‘Cold Maceration’ or ‘Cold Soaking’ mean and what does it achieve?

A

After crushing grapes macerate at low temperature before fermentation starts.

The purpose of this maceration is to extract colour and flavour compounds without tannins.

49
Q

What fermentation process do some winemakers choose in order limit the contact between skin and juice and to, arguably, make a wine with more purity and delicacy?

A

They load the press with whole bunches of uncrushed grapes. The process is gentle, reduces risk of oxidisation and can, potentially, lead to wines with more purity and delicacy.

50
Q

Which of these yeast and bacteria give a plastic, sticking plaster, smoked meat and or leather notes to a wine?

Saccharomyces cerevisiae
Brettanomyces
Lactic bacteria

A

Brettanomyces

51
Q

Which one of these statements about yeast is False?

Commercial yeast strains give a consistency of flavour.
Ambient Yeast strains (wild fermentation) results in wines that may be more complex.
Ambient / Wild yeast strains are more reliable at higher temperatures.
Yeast will not ferment correctly if the temperature is too high or two low.

A

Ambient / Wild yeast strains are more reliable at higher temperatures.

52
Q

In the image below, in red wine making what does the A represent

A

Crush

53
Q

What is the typical range of fermenting red wines?

A

68°F to 90°F

54
Q

Which statement about Ambient Yeast is False?

Ambient Yeast must be kept at an ambient temperature of 18-20°C to ferment correctly
It is found throughout the winery and on the bloom
Adds complexity to the wine but results can be random
Many ambient yeast can be killed off with SO2

A

Ambient Yeast must be kept at an ambient temperature of 18-20°C to ferment correctly

55
Q

Which statement is most correct about inert barrels

Inert barrels do not pass oak flavours to the wine but the wine does typically oxidise.
Inert barrels do pass oak flavours to the wine and the wine does oxidise.
Inert barrels do pass oak flavours to the wine and the wine does not typically oxidise.
Inert barrels do not pass oak flavours to the wine and the wine does not typically oxidise.

A

Inert barrels do pass oak flavours to the wine and the wine does not typically oxidise.

56
Q

Clear or purple/pink crystals in a bottle of wine imply that the wine?

Has been aged in oak barrels
Has not been chilled to stabilise the wine.
Excess sugar from chaptalisation has not dissolved in the wine.
You have one the diamond in the wine competition, you can now retire on your winnings.

A

Has not been chilled to stabilise the wine.

57
Q

In white wine making why is skin contact limited?

A

To reduce the risk of oxidisation, minimize tannin and color extraction.

58
Q

With regard to pressing wine, what does fractions mean?

A

It is different pressing of the same grapes at different pressures to give a mix of blending components.

59
Q

What can happen if grape juice isn’t clarified before fermentation?

A

It can result in creation of unpleasant aromas and fermentation could stop prematurely.

60
Q

How is White Zinfandel made?

A

Same as any other Rose but with Zinfandel grapes

De-stem grapes then Direct Pressing or Short Maceration (actually made by Saignee method!)

Cool ferment at 53~71oF and stop ferment whilst still some resid sugar by cooling and filtering.

NB Some fully fermented, dry, White Zin is also made

61
Q

How would you sweeten grape juice (or finished wine)?

A

Addition of Rectified Concentrated Grape Juice, Sussreserve or sugar Chaptalisation

62
Q

Which one of these is not a method of increasing extraction during wine making?

Pumping over
Press wine

Post fermentation Maceration
MLF

A

MLF

63
Q

What is the main yeast strain used for wine production?

A

Saccharomyces cerevisiae

64
Q

Which is a method of concentrating grape sugars?

Passerillage
Passito
Ice wine production
All of the above

A

All of the above

65
Q

What are Gross Lees?

A

Dead yeast and grape skins that fall out of the wine shortly after fermentation has ended.

66
Q

Which one of these is not an inert vessel?

Epoxy lined concrete tank.
Stainless steel .
A Glass bottle with a screw cap.
Oak barrel.

A

Oak barrel.

67
Q

What is Saignée?

A

Pronounced Sonyay

The saignée method (meaning “bleeding” in French), involves making rosé as a by-product of red wine fermentation, where a portion of the pink juice from the grape must is removed at an early stage, which is fermented separately to produce rosé.

68
Q

List 4 ‘Cap Management’ techniques and briefly outline what they are.

A

Punching Down - Punching the Cap down by hand with paddles on sticks, more latterly done by mechanical paddles.

Pumping Over - Fermenting juice drawn from bottom of vat and pumped up on to the top to wet the Cap.

Rack and Return - Fermenting juice drained into another vessel then pumped back over the Cap.

Rotary Fermenters - Fermentation takes place in rotating horizontal tanks keeping juice in constant contact with skins.

69
Q

What are the 4 most common black grape varieties for high-volume wine making and why are they most suitable?

A

Cab Sav, Merlot, Syrah/Shiraz & Grenache/Garnacha

Because the regions responsible for high-volume wines tend to be warm, sunny and dry and due to the concentration of colours, tannins and flavours, in their skins, they can deliver fruity wines with adequate colour even at high yields.

70
Q

What are the 3 main techniques used to clarify grape juice or finished wine?

A

Sedimentation (Racking)

Fining (adding a fining agent to wine that bonds with particles and causes clumps to form, which are then filtered out.)

Filtration (Depth Filtration, Surface Filtration.)

71
Q

Which is not a by-product of Alcoholic fermentation?

Heat
Flavour
Carbon Dioxide
Sugar

A

Sugar

72
Q

What is a ‘Natural Wine’?

A

A wine that is made with as minimal intervention as possible

73
Q

Which packaging option is best at preserving fresh fruity wines?

Bag in box
Plastic bottles
Glass bottles with Screw Cap
Glass bottles with Cork

A

Glass bottles with Screw Cap

74
Q

Élevegae refers to which stage of wine production?

A

Maturation

75
Q

MLF can be inhibited by which 3 methods?

A

Filtering out the bacteria
Adding SO2 after alcoholic fermentation
Keeping the wine cool

76
Q

Which statement about Skin contact is false?

Colour flavour and tannins are extracted from the skin
The longer the skin contact the more the extraction
Not all red wines are made from skin contact
Many whites are made without skin contact.

A

Not all red wines are made from skin contact

77
Q

Which one of these statements is True?

Fermenting at higher temperatures results in the loss of volatile aromas, particularly floral aromas.
Fermenting at higher temperatures, results in more volatile aromas, particularly floral aromas.
Red wines are less likely to have floral aromas due to their higher fermentation temperature.
Lower temperatures encourage the development for fruity character.

A

Fermenting at higher temperatures, results in the loss of more volatile aromas, particularly floral aromas.

78
Q

Which statement is true about Small barrels?

They have the largest effect on wines, giving more flavour, tannins and oxidative effects
They have less effect on the wine. giving less flavour. tannins and oxidative effects
Are much cheaper to make and use so are more cost effective.
Are perfect for barrel fermentation of red wines

A

They have the largest effect on wines, giving more flavour, tannins and oxidative effects

79
Q

Which one of these will not stop fermentation?

Lowering the temperature to near 0°C
When the alcohol rises to over 15% abv
Adding SO2
Chaptalisation

A

Chaptalisation

80
Q

Which one of these is not required if the grapes are mechanically harvested?

Adjustments.
Sorting.
Pressing.
Destemming & Crushing.

A

Destemming & Crushing.

81
Q

Which is not an example of Clarification?

Sedimentation
Finning
Millerandage
Filtration

A

Millerandage

82
Q

List 3 things you might want to stabilise your wine against

A

Tartrate

Microbiological

Oxygen

83
Q

What bacteria converts Malic acid to Lactic acid?

A

Lactic bacteria

84
Q

What is ‘Cap Management’ and what does it achieve?

A

The ‘Cap’ is the mass of pulp and skins on the surface of the wine, if left to float little colour, flavour or tannin will be extracted.

‘Cap Management’ is one of the processes to to keep the pulp and skins in contact with the fermenting juice.

85
Q

Identify/describe 2 techniques that are used to impart aromas of hazelnut, butter, sweet spice, toast and vanilla with a rich texture and full body to Chardonnay

A

MLF:

process that occurs after regular alcoholic fermentation, bacteria converts malic acid to lactic acid. This lowers acidity and contributes buttery aromas.

Oak Aging w/new small barrels:

Imparts aromas of sweet spice, toast, vanilla. Barrels can be used during fermentation and/or maturation. Old/large barrels would not impart as intense flavors. Oak also adds tannin, which increases texture and body of wine.

86
Q

Racking is the process of:

A

Removing wine from its sediment by slowly and gently pumping it into a different vessel.

87
Q

What process guarantees microbiological stability in wine?

A

Sterile Filtration

88
Q

What style of wine is produced from Carbonic Maceration?

A

Lively, refreshing, easy-drinking reds.

Lower tannins and lighter color.

Fresh, fruity, flavors of banana, kirsch, bubblegum and cinnamon.

89
Q

What is Chaptalization and its purpose?

A

Adding RCGM to wine before/during fermentation.

Increases sugar levels in order to raise the potential alcohol level of a wine.

Used in regions where a cool climate produces insufficient sugar in grapes in order to reach a satisfactory level of alcohol.

90
Q

Chilling the wine to 0 degrees C to form crystals is a form of:

A

Tartrate stabilization.

91
Q

How does the size of the fermentation vessel affect the speed and temperature at which a wine ferments (assuming there is no temperature control)?

A

Small vessels provoke slow, cool fermentations

Large vessels lead to short, hot fermentations.

92
Q

What are the French terms for free-run wine and press-wine?

A

Vin de Goutte

Vin de Presse

93
Q

In relation to fermentation, when would “saignage” most likely occur?

A

After fermentation.

94
Q

Which method is used to adjust alcohol after fermentation?

A

Reverse Osmosis.

95
Q

Reverse Osmosis is ____ in EU countries.

A

allowed.

96
Q

What winemaking process is shown in the image?

A

Bâtonnage / Lees Stirring

97
Q

What is the French term for pumping over the cap?

What is the French term for punching down?

A

Remontage

Pigeage

98
Q

What is the French term for “rack and return”?

What is the French term for “racking”?

A

Délestage

Soutirage

99
Q

What are the 3 barrel making stages from beginning to end?

A

Warming / Shaping / Toasting

100
Q

By which passage does an oak barrel stop imparting flavor to a wine?

A

By the 4th to 6th passage.

101
Q

What are the 2 species of oak tree used for French barrels?

What is the species used for American barrels?

A

Quercus robur / Quercus petraea

Quercus alba

102
Q

How are French and American oak cut differently and why?

A

French oak is split rather than sawn, a technique that produces fewer staves but prevents leakage in the final barrel.

American oak is less porous and can be sawn without fear of leakage, but this method releases more vanillin and lactones, resulting in the coconut character of American oak

103
Q

How are French and American oak staves dried differently, and how does this affect the flavors they impart?

A

French oak is usually air-dried, a gentle process that leaches out some of oak’s more aggressive tannins and flavors.

American oak is quickly kiln-dried, and lactones are concentrated.

104
Q

Which acid is most common in Vitis vinifera grapes?

A

Tartaric Acid

105
Q

What is a Tun and what is its capacity?

A
  • A large beer/wine cask.
  • Equal to 4 hogsheads (roughly 950L)
106
Q

Where are Puncheons commonly used and what is their capacity?

A
  • Commonly used in Australia.
  • Holds 450-500L
107
Q

Cold stabilisation is done to remove unstable tartrates - how is this done?

A

Cold stabilisation

  • chill the wine down to between -4 to -8 degrees and storing it in an insulated tank for eight days
  • potassium bitartrate crystals will drop out
  • wine can be racked off the crystals
108
Q

Protein instability in white wines is a major issue - how is this treated generally, and what are the considerations when using it

A

Protein Instability

White wine often contains unstable proteins that may cause a haze cloudiness or a deposit to develop if the wine is subjected to either hot or cold temperatures

so leaving a white wine which hasn’t been treated for protein instability is likely to come out hazy on a hot day!

The treatment for protein is bentonite fining

the things to remember is:

  • the test for protein stability is to take a sample of the white wine and keep it warm for a while and you will have a milky deposit at the bottom of the wine
  • do careful trials with bentonite because it will strip flavour and aromas from the wine as well as the proteins
  • do two bentonite finings to ensure all the proteins are removed