Vinification (cont.) Flashcards
1
Q
What does alcohol contribute to a wine?
A
Body, weight, warming sensation, sweet smell and taste, sometimes bitterness.
2
Q
What two acids come from the grape itself?
A
- Tartaric acid
2. Malic acid
3
Q
What are two acids produced in fermentation or MLC?
A
- Acetic acid (VA)
2. Lactic acid
4
Q
What does acidity contribute to?
A
- Structure
2. Makes wine refreshing
5
Q
What is the sum of all the acids called, and measured in what?
A
Total Acidity
grams per litre (g/L)
6
Q
Aromatics come from 4 sources. What are they (give an example for each)
A
- Grape, e.g. Methoxyprazines (Sauv. Blanc - grassy)
- Fermentation due to presence of aroma precursors in grape must, e.g. Terpenes (Muscat - grapey)
- Aromas originating from fermentation and its by-products (Esters - Isoamyl Acetate (banana) - Beaujolais)
- Other sources, e.g. oak maturation
7
Q
What does glycerol contribute to?
A
Smoothness and fullness
8
Q
Define Phenolics
A
An important group of compounds that occurs in grapes - skins, stems, and seeds.
9
Q
Name two types of phenolics
A
- Anthocynanins (colour pigments)
2. Tannins (binds with proteins in mouth, giving a drying sensation)
10
Q
What are the 4 main winemaking approaches?
A
- Conventional
- Organic
- Biodynamic
- Natural
11
Q
Define Conventional Winemaking
A
Includes additions, manipulations, temperature-control, clarification, stabilisation. Louis Pasteur 1860 foundations.
12
Q
What are the advantages and disadvantages of Conventional winemaking?
A
Adv = Consistency of style, stable product, expressiveness (allows you to more easily show grape variety).
Dis = Industrial wine (more of a product than artisan).
13
Q
Define Organic Winemaking
A
Making wine with certified organically-grown grapes and complying with rules that restrict certain practices from being performing during winemaking process.
Can still use cultured yeasts and additions.
14
Q
What are the advantages and disadvantages of Organic Winemaking?
A
Adv = eco-friendly, high consumer acceptance
Dis = In States, not allowed to use SO2, so affects stability, no synthetic chemicals (risky), certification adds cost.
15
Q
Define Biodynamic Winemaking
A
Wine must be made from certified biodynamically grown grapes. Ambient yeasts are encouraged (commercial still allowed), Demeter (regulating body).
16
Q
What are the advantages and disadvantages of Biodynamic Winemaking?
A
Adv = Eco-friendly, high-consumer acceptance, certified body, can still use SO2 (within guidelines).
Dis = No synthetic chemicals (risky), certification adds cost.
17
Q
Define Natural Winemaking
A
Aim is “nothing added, nothing removed”. Minimal manipulations. No regulating body, so anything goes!
18
Q
What are the advantages and disadvantages of Natural Winemaking?
A
Adv = Bottle variations, fashionable and quirky, a niche hipster following, grown in popularity because of sulfite concern.
Dis = Bottle variations, suppresses varietal expression, less stable, less consistency, only suitable for small-scale production, no regulating body.
19
Q
What are the 3 main threats during grape transportation to the winery?
A
- Oxygen
- Ambient yeasts
- Acetic acid bacteria
20
Q
What are 3 examples when grapes are not destemmed?
A
- Whole-bunch fermentations (e.g. Pinot Noir in Burgundy)
- Carbonic & Semi-carbonic maceration (e.g. Gamay in Beaujolais)
- Whole-bunch pressing for white wines (e.g. high-quality sparkling)
21
Q
Define crushing
A
The application of sufficient pressure to the grapes to break the skins and release the juice, making it available for fermentation.
22
Q
What is ‘Must’?
A
The mixture of grape juice, pulp, skins and seeds that comes from the crusher.
23
Q
Define Pressing
A
Separating the liquids from the solids.
24
Q
What is the most common form of yeast used in winemaking?
A
Saccharomyces Cerevisiae
25
What is the cool fermentation temp., and what style is it used for?
12'-16'C
Fresh, fruity white wines and roses
26
What is the mid-range fermentation temp., and what style is it used for?
17'-25'C
Easy-drinking, fruity red wines, or barrel fermented white wines (mid of range)
27
What is the warm fermentation temp. and what style is it used for?
26'-32'C
Red wines with pronounced flavour concentration and high tannins.
28
Define Malolactic Conversion (MLC)
The result of lactic acid bacteria converting malic acid into lactic acid and carbon dioxide, and it produces heat.
29
What are the 3 conditions that allow MLC to occur?
1. 18'-22'C
2. A moderate PH (3.3-3.5)
3. A low total SO2
30
What 3 conditions prevent MLC from occuring?
1. Below 15'C
2. a low pH
3. moderate levels of SO2
31
What is Lysozyme?
An enzyme that kills lactic acid bacteria, added to wine to stop MLC taking place.
32
Define Reverse Osmosis
A form of cross-flow filtration that removes a flavourless permeate of alcohol and water, which can be distilled to remove the alcohol, and then blended back in.
33
Define Spinning Cone
A device that first extracts volatile aroma compounds from wine and then removes the alcohol.
34
What are the benefits of oxidation in maturation? (4)
1. Development of tertiary aromas
2. Influence colour
3. Greater colour stability and intensity
4. Softening of tannins
35
Define micro-oxygenation
Involves bubbling oxygen through wine generally in a stainless steel tank.
36
What are the advantages and disadvantages of micro-oxygenation?
Adv = increase colour stability and intensity, soften tannins, improve texture, reduce unripe, herbaceous flavours. Cheaper as doesn't need expensive barrels, better control.
Dis = new technique so research is limited, provide favourable environment for spoilage organisms.
37
What are 2 oak barrel alternatives?
1. Oak chips
| 2. Oak staves
38
Define lees
The sediment that settles at the bottom of a wine container, containing dead yeast, dying yeast and bacteria, grape fragments, precipitated tannins, and nutrients.
39
Define Gross Lees
Sediment that forms quickly after the end of fermentation.
40
Define Fine Lees
Smaller particles that settle more slowly and gradually form a sediment.
41
Define Racking
The process of transferring wine from one vessel to another with the aim of removing sediment from the wine.
42
Define Blending
The mixing together of two or more batches of wine.
43
In which situations might you choose NOT to blend? (2)
'Single Vineyard' (rare and distinctive - marketing), aromatic grapes with pronounced aromas (Sauvignon Blanc)
44
What are the normal pre-bottling maturation times for whites and reds?
12-24 months - Reds
| 6-12 months - Whites
45
Define clarification
All the processes, physical and chemical, that are used to make wine clear.
46
What are the advantages and disadvantages of sedimentation?
Adv = avoids potential loss of flavour and texture, highly suitable for premium wines, no specialist equipment needed.
Dis = takes time so costly - it cannot be sold until it is clarified and ready to be released.
47
Define Centrifugation
A rapid process that spins the wine at a high speed to clarify it.
48
What are the advantages and disadvantages of centrifugation?
Adv = Fast - allows early bottling.
Dis = very expensive - only suited to high-volume or super-premium, you're likely to introduce oxygen.
49
Define Fining
A fining agent is added to speed up the process of the precipitation of suspended material in the wine. It removes a small proportion of unstable colloids.
50
Define Filtration
A physical separation technique used to eliminate solids from a suspension by passing it through a filter medium consisting of porous layers that trap solid particles, thus making the liquid clear.
51
Define Stabilisation
Refers to several winemaking interventions which, if not carried out, could lead to undesired effects in the finished wine.
52
What is Electrodyalisis?
This process uses a charged membrane to remove selected ions.
53
What is Ion Exchange?
This process does not remove tartrates, but instead, it replaces potassium and calcium ions with hydrogen or sodium ions, which will not drop out of the solution.
54
What is Carboxymethylcellulose (CMC)?
This cellulose is extracted from wood, and prevents tartrates from developing to a visible size.
55
What is Metatartaric Acid?
Adding this compound prevents the growth of potassium bitartrate and calcium tartrate crystals, reducing the need for cold stabilisation.
56
What is a risk when wines have residual sugar?
They are liable to potentially start to re-ferment in the bottle.
57
What are 2 ways to deal with microbiological stability?
1. Removing yeast through sterile filtration.
| 2. Adding sorbic acid or SO2
58
What are 3 things that might be adjusted prior to bottling?
1. SO2 levels
2. Reducing dissolved oxygen
3. Adding CO2
59
How do you check that the level of sulfur dioxide (SO2) is within legal limits?
Both the total SO2 and the free SO2 are measured.
| Free SO2 contains molecular SO2 which is the effective part.
60
What are the general amounts of free SO2 in white, red and sweet wine?
```
White = 25-45 mg/L
Red = 30-55 mg/L
Sweet = 30-60 mg/L
```
61
What is the risk of dissolved oxygen in a wine?
It can accelerate ageing and reduce shelf life.
62
Define 'Sparging'
Removing dissolved oxygen by flushing it with an inert gas if the levels are found to be too high.
63
Why might Carbon Dioxide (CO2) be added to a wine before bottling?
To give it a slight spritz and make it more refreshing - used for inexpensive, youthful white and rose wines.
64
Why might a wine go cloudy/hazy in a bottle?
The growth of bacteria in the wine coupled with failure to filter it adequately.
65
How can cloudiness in bottle be prevented? (3)
1. Better winery hygiene
2. Pre-bottling chemical analysis
3. Filtering wine to remove yeast or bacteria
66
What is a protein haze?
Where fining has not been effective, due to either:
1. fining not working
2. wrong fining agent being used
3. over-fining
67
Define Tartrates
Colourless or white crystals in the bottom of bottle that can be mistaken for fragments of glass.
68
Excessive Volatile Acidity contributes to...
a pungent smell of nail varnish and/or vinegar
69
What is excessive VA due to? (3)
1. activity of acetic acid bacteria
2. inadequate levels of SO2
3. excess exposure to oxygen
70
How can excessive volatile acidity be avoided? (5)
1. sorting fruit to exclude damaged grapes
2. scrupulous hygiene
3. avoiding ullage
4. careful racking
5. maintaining adequate SO2 levels
71
What are reductive smells caused by? (1)
High levels of volatile, reductive sulfur compounds.
72
What causes reduction? (3)
1. Yeast under stress (inadequate levels of nitrogen in winery)
2. near complete exclusion of oxygen in closed vessels during ageing
3. impermeable style of screwcap
73
Define Light Strike (fault)
A wine fault caused by UV radiation and certain wavelengths of visible light reacting with some compounds in the wine to form volatile sulfur compounds.
74
How would you identify Light Strike?
A smell like dirty drains
75
What is Brettanomyces?
A yeast
76
How would you identify Brettanomyces?
Animal, spicy, or farmyard smells
77
How can Brettanomyces be avoided? (3)
1. Excellent hygiene
2. Maintaining effective SO2 levels
3. Keeping pH levels low and keeping the period between the end of alcoholic fermentation and MLC as short as possible.
78
How can you treat Brettanomyces if your wine has been infected? (2)
1. Filtration
| 2. DMDC (dimethyl dicarbonate)
79
What is the risk of too much oxygen when bottling (3) and the too little oxygen (1)?
Too much = premature browning, shorter shelf life, oxidised characters (bruised apple)
Too little = reductive characteristics (onion, rotten egg)
80
What is 'Total Package Oxygen' a combination of? (4)
1. the amount of dissolved oxygen
2. the oxygen in the head space
3. the amount of oxygen in cork or other closure
4. the oxygen transmission rate (OTR) of the cork or closure
81
What are the the advantages and disadvantages of plastic bottles (PET)?
Adv = stability, 0% oxygen transmission, strong, recyclable, lighter (1/8th weight of glass), tough, quick consumption in informal settings.
Dis = lower consumer acceptance, not eco-friendly
82
What are the advantages and disadvantages of Bag-in-Box?
Adv = cheap, long shelf life, good protection from oxygen after wine has been poured, easy to store (stackable), recyclable, various sizes, consumer acceptance is getting better (very popular in Australia).
Dis = Quality of tap is very important as this is where most oxygen ingress occurs, laws (some places won't allow)
83
What is 'Brick' aka. Tetra Pak?
A bottle alternative made of paper card with plastic layers, and an aluminium foil layer that excludes oxygen and light.
84
What are the advantages and disadvantages of 'Brick'?
Adv = can be entirely filled with wine (so excluding oxygen and light), good where price is a major factor (Germany), contemporary designs
Dis = filling equipment is a big investment, low-consumer acceptance overall
85
What are the advantages and disadvantages of Cans
Adv = Light weight, robust, easy to open, impermeable to oxygen (and light), recyclable.
Dis = filling equipment is a big investment, producers will outsource filling of cans, low consumer acceptance.
86
What are the advantages and disadvantages of a Natural Cork closure?
Adv = light, flexible, comes from a renewable natural source, recyclable, slow ingress of oxygen, high-consumer acceptance.
Dis = can be v. expensive, need a specialised tool to remove it, at risk from TCA (cork taint).
87
How can the risk of TCA (cork taint) be reduced? (4)
1. clean corks with steam extraction
2. using technical corks
3. rigorous quality control (gas chromatography)
4. inexpensive polymer barrier between cork and wine
88
What are 2 types of technical cork?
1. Agglomerated cork (cork bits glued together)
2. One-plus-one cork (the largest, central section is inexpensive agglomerate, but it is finished with a disk of natural cork at both ends).
89
What are the advantages and disadvantages of a technical cork closure?
Adv = incidents of cork taint are less, addresses the issue of cost AND avoiding cork taint.
90
What are the advantages and disadvantages of plastic closures (aka. synthetic corks)?
Adv = much cheaper, different colours, no additional cost or logistical issue in switching between them and natural corks.
Dis = tend to shrink with time, not suitable for ageing, flavour-scalping (the loss of some flavour intensity because plastic absorbs some flavour molecules).
91
Define synthetic corks.
Closures made of food-grade plastic with a silicone coating.
92
Define a screwcap.
An aluminium closure rolled onto the outside of a bottle neck that has been specially designed for this purpose.
93
What are the advantages and disadvantages of a screwcap closure?
Adv = cheap, easy, no opening device needed, controlled, consistent, easily reclose it, increasing consumer acceptance (especially English speaking countries)
Dis = needs expensive equipment (additional equipment cost than natural cork), reductive issues.
94
Define a glass stopper.
A closure made from glass, but where the actual seal is formed by a plastic ring.
95
What are the advantages and disadvantages of a glass stopper closure?
Adv = attractive, can be stored as long as natural corks, no cork taint risk.
Dis = as expensive as top-quality cork, special bottles needed.
96
What are the conditions needed for bottle ageing? (5)
1. cool, dark place
2. constant temperature
3. 10'-15'C
4. constant humidity
5. lying on their side
97
What are the 3 procedures for hygiene in the winery? (3)
1. Cleaning
2. Sanitation
3. Sterilisation
98
What is a lot number (1), and what does it enable wineries to do (3)?
Each consignment of wine is given a 'lot number' which appears on the bottle.
It allows:
1. trace back where grapes came from
2. what additives have been used
3. what processes the wine went through
99
Define skin contact
the process of leaving the juice in contact with the skins to extract compounds from the skin.
100
What are the 2 main purposes of skin contact for white wines?
1. To enhance the extraction of aroma compounds and precursors.
2. To enhance the texture of the wine (by extracting a small amount of tannin)
101
What white grapes is skin contact typically used on?
Aromatic grape varieties (Riesling, Sauvignon Blanc)
102
What are the risks of keeping white grapes in contact with their skins? (4)
1. increased oxygen contact
2. cost (hold wine in vessels)
3. may over-extract (some winemakers think it can suppress varietal expression)
4. Time (1 hour - 24 hours)
103
What are white wines called that are fermented on their skins, and what are their characteristics?
Orange wines
Tannin
Dried fruit, dried herbs, nuts, hay
104
Define Free Run Juice
If grapes are destemmed and crushed, it is the juice that can be drained off as soon as the grapes are crushed.
105
What are 3 characteristics of Free Run Juice?
1. lowest in solids, tannin and colour
2. more sugar and sweeter (disrupting mainly the pulp)
3. more acidity
106
Define Press Juice
The juice that runs off through the pressing.
107
What are 4 characteristics of Press Juice
1. More solids, tannin and colour are extracted
2. More bitterness
3. Less acidity
4. Higher proportion of nutrient for the yeast.
108
Define 'Press Fractions'
Separating the press juice into different fractions as the pressing continues.
109
Define Hyperoxidation
The technique of deliberately exposing the must to large quantities of oxygen before fermentation.
110
What happens during Hyperoxidation?
The compounds in the must that oxidise most readily turn brown. However, during fermentation, these compounds precipitate, turning the wine to its normal colour.
111
What is the main aim (and an added benefit) of Hyperoxidation? (2)
To produce wines that are more stable against oxidation after fermentation.
Also helps remove bitter-tasting compounds.
112
What are the risks of Hyperoxidation? (5)
1. Overdoing it
2. Not well-suited to aromatic varieties as it can destroy some of the volatile aroma compounds
3. Increased chance of microbial spoilage.
4. Sulfur dioxide will be wiped out
5. Cost - needs specialised skillset and increased labour
113
Why would you want to not over-clarify the must before fermentation?
1. A small amount of solids provide nutrients for the yeast.
2. Less chance of a 'stuck' fermentation
3. Solids give greater array of aromas, and thus complexity
4. Solids can add to the texture of the wine
114
What are 4 pre-fermentation clarification methods?
1. Sedimentation
2. Clarifying agents
3. Flotation
4. Centrifugation
115
Explain Flotation
Involves bubbling gas up through the must. As bubbles of gas rise, they bring up solid particles. The solid particles are then skimmed off the top of the vessel.
116
What are the advantages and disadvantages of Flotation?
Adv = Can also be used as a method of hyperoxidation (using oxygen as your gas), effective and quick, batch or continuous process, cost and energy-saving (must does not need chilling).
Dis = can only be used on must, not wine, fining agents must be added to the must for it to work, needs gas, fining agents, and specialist equipment for bubbling the gas.
117
Explain Centrifugation
A centrifuge is a machine that comprises a rapidly rotating container which uses centrifugal forces to separate the liquids from solids.
118
What are the advantages and disadvantages of Centrifugation
Adv = clarifies the must quickly, used continuously (saves time and labour cost), can be used on must and wine.
Dis = high capital cost, increase the must's exposure to oxygen.
119
Explain Clarifying Agents
A number of different compounds can be added to the must as processing aids to speed up the rate of sedimentation. E.g. Pectolytic enzymes break down pectins in the must.
120
What are the advantages and disadvantages of Clarifying Agents?
Adv = Despite the capital cost, the time and energy saved compared to other methods is significant.
Dis = Capital cost, can only be used on must.
121
When will Stainless Steel Tanks be used?
Production of fruity, white wines.
122
What are the benefits of Stainless Steel as a fermentation vessel?
temperature can be controlled easily, and therefore easy to maintain cool fermentation conditions.
123
What are 2 typical white grapes that would be fermented in Stainless Steel vessel?
1. Pinot Grigio
| 2. Sauvignon Blanc
124
What are 2 white grapes that might be fermented in a concrete vessel?
1. some styles of Chablis
| 2. white Rioja
125
What white grape might be fermented in old or new oak barrels?
Premium or super-premium Chardonnay
126
What is meant by "stopping the fermentation"?
Stopping the fermentation process before all sugars have been converted, resulting in a wine with residual sugar.
127
How can you stop the fermentation? (5)
1. Chilling to below 10'C
2. Adding a high dose of SO2 to inhibit the yeast.
3. Filtration - 0.45 microns hole size.
4. Sterile filtered - to ensure fermentation does not start again at a later stage.
5. Fortification
128
What are the advantages and disadvantages of "stopping the fermentation"?
Adv = winemaker has control over level of sugar in the final wine, quick, simple and low risk, low cost.
Dis = rare to find the same intensity and/or complexity as concentrating the grape must, tends to not reach outstanding levels of quality.
129
What wine is made by "stopping the fermentation"?
White Zinfandel
| moscato d'asti?
130
What is another way of making a sweet wine that doesnt involve concentrating grape sugar
Blending in a sweetening component.
131
Describe blending in a sweetening component.
The dry wine is stored until it is ready to be bottled, and the sweetening component is blended in.
132
How is "blending in a sweetening component" done, and the qualities of each? (2)
1. RCGM (rectified concentrated grape must) - just contains sugar from grape (clear and colourless)
2. Unfermented grape juice (aka. Sussreserve) - gives a grape juice-like character.
133
What are the advantages and disadvantages of blending in a sweetening component to make a wine with residual sugar?
Adv = storing dry wines are less susceptible to spoilage organisms than wines with residual sugar, winemaker is able to trial, measure and add the amount of sweetener needed, control and consistency, maintain or slight increase the volume of final wine, cheap to produce.
Dis = Only makes acceptable - good quality, regulations (use of sugar not permitted in EU)
134
What are 6 factors that affect extraction?
1. Temperature
2. Time on skins
3. Alcohol level
4. Grape variety
5. Techniques used
6. Medium in which the extraction is taking place
135
Define anthocyanins
The source of colour in red wines.
136
When do anthocyanins become more stable, and what facilitates this? (2)
When they combine with tannins (resulting in colour stability).
Oxygen facilitates this reaction.
137
What is the key aim of maceration before fermentation for red wines?
To extract colours and flavours, without extracting tannins.
138
What are two other names for 'Cold Soaking'? (2)
1. Cold Maceration
| 2. Pre-fermentation Maceration
139
Explain 'Cold Soaking'
The juice and skins are chilled (around 4'-10'C) for 3-7 days. Punching down and/or pumping over is done to aid extraction.
140
What are the advantages and disadvantages of 'Cold Soaking'?
Adv = gentle, easy to monitor and control, slow extraction, premium wines.
Dis = cost (requires chilling), time taken
141
What grape is 'Cold Soaking' typically carried out on, and why? (2)
Pinot Noir
Because it has a low level of anthocyanins
142
What are two techniques of macerating with heat?
1. Flash Detente
| 2. Thermovinification
143
Why would a winemaker choose to macerate with heat?
To extract high levels of anthocyanins and flavours quickly.
144
Define 'Thermovinification'.
The must is heated to 50'-60'C from a number of minutes to several hours.
145
Define 'Flash Detente'
Destemmed grapes are quickly heated to 85'-90'C and then rapidly chilled in a vacuum after for 1-2 minutes. This process bursts the cells in the grape-skins, allowing a very rapid extraction of anthocyanins and flavours.
146
What are the advantages and disadvantages of Thermovinification?
Adv = Fast, beneficial if grapes are exposed to botrytis (grey rot) because the high temps denature oxidative enzymes, intensify fruitiness of wines.
Dis = can lead to a reduction in more subtle varietal characters.
147
What are the advantages and disadvantages of Flash Detente?
Adv = beneficial if the grapes are exposed by botrytis (grey rot) or smoke taint, can be used as a treatment, it can denature enzymes than can disrupt fermentation, good for neutralising spoilt fruit, fast, intensify fruitiness of wine.
Dis = high capital cost, over-extraction, can lead to a reduction in more subtle varietal characters
148
Define a 'cap'.
When the grape skins rise to the top of the liquid in fermenting must, and remain there, buoyed by carbon dioxide.
149
What are 4 reasons for mixing the cap?
1. The skins macerate amongst the whole liquid rather than just the top (distributed)
2. a dry cap would allow bacteria to convert alcohol into unwanted acetic acid.
3. Aerate the must (avoiding the production of reductive sulfur compounds)
4. distribute heat (temp monitoring and control)
150
What are 5 Cap Management techniques?
1. Punching Down
2. Pumping Over
3. Rack and Return
4. Ganimede Tanks
5. Rotary Fermenters
151
Define 'Punching Down'
A plunger is used to submerge the cap of grape skins in the liquid.
152
What is another name for 'Punching Down'?
Pigeage
153
What are the advantages and disadvantages of 'Punching Down'?
Adv = gentle, can be mechanised, open-top vessels allow for aeration
Dis = may be not intensive enough, very labour intensive without mechanisation (cost)
154
Define 'Pumping Over'
Juice/wine is taken from near the bottom of the vessel and sprayed over the cap of skins.
155
What are the advantages and disadvantages of 'Pumping Over'?
Adv = very gentle, introduce oxygen (yeast needs to build its numbers during the 'lag' phase, and avoids unwanted reductive flavours), mechanised.
Dis = need to use other methods also for more tannins and colour, needs more specialist equipment (cost), if you wanted a fruit-forward style, you'd want something that didn't splash the juice as much.
156
What is another name for 'Pumping Over'?
Remontage
157
Explain 'Rack and Return'
Similar to pumping over; however, the juice is pumped from one vessel into another vessel. The cap of skins falls down the vessel. The juice is then pumped from the new vessel in through the top of the original vessel and is sprayed over the skins. This breaks up the cap and mixes the juice and skins thoroughly.
158
Why is 'Rack and Return' done, and on what 2 grapes? (3)
Because it is more extractive, and when a wine is wanted that has medium-high levels of flavour, colour and tannin.
Cabernet Sauvignon, Syrah-based
159
What are the advantages and disadvantages of 'Rack and Return'?
Adv = extracts more flavour, colour and tannins, more extractive so may be used only 1-3 times during fermentation.
Dis = cannot be fully automated so labour intensive, requires labour to set-up and monitor, requires a clean vessel.
160
What is another name for 'Rack and Return'?
Delestage
161
Explain Ganimede Tanks
Specialised tanks that bubble CO2 up through the must/wine. Pressure builds up under the cap, until finally, the cap bursts.
162
Why are Ganimede tanks used, and for what style wine? (2)
It is more extractive, so when you want medium to high levels of flavour, colour and tannin.
Cabernet Sauvignon and Syrah-based.
163
What are the advantages and disadvantages of Ganimede Tanks?
Adv = can be automated, much less labour intensive, can aerate with oxygen.
Dis = specialist tanks (high capital cost)
164
Explain Rotary Fermenters
Horizontal, closed, stainless steel tanks. The whole tank rotates and internal blades break up the cap.
165
When would 'Rotary Fermenters' be used? (2)
For heavy extraction, e.g. Cab Sav or Syrah
| Inexpensive, high-volume wines
166
What are the advantages and disadvantages of 'Rotary Fermenters'?
Adv = can be programmed, low labour requirements, very effective at extracting.
Dis = very aggressive, relatively expensive tanks compared to standard stainless steel tanks, large volumes of wine need to be fermented in them to make them cost-effective.
167
What are 2 less common maceration options during fermentation?
1. Must concentration
| 2. Co-fermentation
168
Explain 'Must Concentration'
The levels of tannin, colour and flavours of the wine can be increased by drawing off some of the juice just after crushing, concentrating the remaining must.
169
Define 'Co-fermentation'
The process of fermenting different grape varieties together in the same vessel. A small proportion of white grapes (up to 5%) within a red wine fermentation.
170
What are the advantages and disadvantages of co-fermentation?
Adv = increase colour intensity and stability, added benefit of aromatic diversity.
Dis = adding too much of the white grape variety can dilute flavours.
171
Which region is co-fermentation typically used, and with what grapes? (2)
Rhone Valley
Viognier and Syrah
Southern Rhone - Viognier, Marsanne and Rousanne.
172
What is the objective of whole bunch/berry fermentations?
To create an oxygen-free environment for the un-crushed fruit.
173
What are the 5 outcomes of whole bunch/berry fermentations?
1. The grapes change from aerobic respiration to anaerobic (without oxygen) respiration.
2. The sugar in the grapes in converted to alcohol (intracellular fermentation)
3. Malic acid is used up (up to 50% and acidity goes down)
4. Increase in glycerol produce (creamier texture)
5. Distinctive aromas are created inside the grape (bubblegum, banana, kirsch, cinnamon)
174
Define anaerobic respiration
Means 'without air' and the grapes producing energy without oxygen.
175
Define aerobic respiration
Means 'with air' and the grapes producing energy with the use of oxygen.
176
Define 'intracellular fermentation'
The sugar in grapes is converted to alcohol without the involvement of any yeast or oxygen.
177
Explain 'Carbonic Maceration' (5)
1. Placing only whole, uncrushed bunches into vessels that are filled with CO2 to remove all oxygen.
2. Intracellular fermentation begins.
3. At 2% alcohol, grapes split open.
4. Grapes are pressed at this stage to separate the juice from their skins.
5. Yeast then completes the fermentation off the skins.
178
Why would a winemaker choose for his grapes to undergo Carbonic Maceration? (5)
1. Extracts colour from the grapes, but little tannin.
2. Fruity, candy-like flavours
3. Oak is not needed (it will clash with fruity candied flavours), so time and cost is kept lower.
4. Flavours are distinct (though not complex)
5. It may improve grapes grown at high yields or that have not reached full ripeness.
179
Which grape, region, and style wine is Carbonic Maceration found? (3)
1. Gamay
2. Beaujolais
3. Beaujolais Nouveau
180
Explain 'Semi-Carbonic Maceration' (8)
1. The vessel is not filled with CO2.
2. The vessel is filled with whole bunches.
3. The grapes at the bottom are crushed under the weight of the grapes above, and some juice is released.
4. Ambient yeast starts to ferment this 'released' juice, emitting CO2.
5. CO2 then causes intracellular fermentation to take place in the remaining intact grapes.
6. At 2%, these intact grapes will burst.
7. The grapes are pressed.
8. Yeast then completes the fermentation off the skins.
181
What is a good way to remember semi-carbonic maceration? (2)
Bottom - normal fermentation
| Top - intracellular fermentation
182
Why would a winemaker choose for his grapes to undergo Semi-Carbonic Maceration? (5)
1. More concentration, body, and tannin.
2. Longer ageing capacity.
3. Better integration of aromas from intracellular fermentation with aromas from grape variety.
4. More stable colours.
5. Less carbonic flavours.
183
Which 5 grapes and for what style might Semi-Carbonic Maceration be used on? (5)
Fruity styles of:
1. Pinot Noir
2. Malbec
3. Tempranillo
4. Gamay
5. Carignan
184
Explain 'Whole Berries/Bunches with Crushed Fruit Fermentation'
Whole berries/bunches are mixed with crushed grapes in the fermenting vessel at the start of fermentation.
The whole berries/bunches are largely submerged by the crushed grapes and kept away from oxygen, therefore intracellular fermentation takes place.
185
Why would a winemaker choose for his grapes to undergo 'Whole Berries/Bunches with Crushed Fruit fermentation'?
1. Winemaker is in control of how many bunches goes in, and therefore, the desired carbonic qualities.
2. More fruit-forward, colourful, less tannin (than just crushed fruit)
3. Gives a smoother texture, and more vibrant and fresh primary aromas (than crushed fruit fermentations).
186
What is the difference between whole berries and whole bunches?
Berries are intact, destemmed grapes. Bunches are berries still on the stem.
187
A winemaker wants to make a fruity, low tannin red wine. What temperature would he ferment at?
A relatively cool temperature of 20'C.
188
A winemaker wants to make a more extracted red wine, with concentration and tannin structure to age. What temperature would he ferment at?
Slightly warmer temperatures of 30'C.
189
What are the benefits to fermenting red wine in oak vessels? (2)
Gives a rounder mouthfeel to the wine, and leads to better integration of oak compounds during maturation.
190
Why might a winemaker ferment a red wine in old large oak or stainless steel vessel? (1)
Retain fruit flavours
191
What are the advantages and disadvantages of post-fermentation maceration?
Adv = improves tannin structure and texture, improves wine's ageing potential.
Dis = takes up time and space (cost), only therefore used on premium or super-premium wines.
192
When is pressing done on red wines?
After fermentation - free run wine will be drained from fermentation vessel and then mass of grape skins removed to be pressed.
193
What are 3 different timings when red wines will be pressed, and how will they make a difference to the style produced? (3)
1. At 2% alcohol (carbonic maceration) - medium levels of colour, fruity flavours, low tannin.
2. After a period of post-fermentation maceration - maximised tannin structure.
3. Straight after alcoholic fermentation is complete
4. Just before the end of alcoholic fermentation - finishes during maturation, and leads to better integration oak flavours and rounder mouthfeel.
194
What are the 3 ways of making Rose wines?
1. Direct Pressing
2. Short Maceration
3. Blending
195
Explain 'Direct Pressing' in rose production.
The grapes of a black grape variety are either whole bunch pressed or destemmed and immediately pressed to minimise any maceration.
196
How are roses made by 'Direct Pressing' fermented?
In the same way as white wines - cold fermentation.
197
What are the characteristics of a rose made by 'direct pressing'? (2)
1. Extremely light in colour and flavour
| 2. Fresh and easy to drink.
198
Which region will you commonly find roses made by 'direct pressing'? (1)
Cotes de Provence
199
Explain 'Short Maceration' in rose production.
The black grapes undergo a short period of pre-fermentation maceration before pressing. Ranges from a couple of hours to a few days in contact with the skins. The juice will be drained, and the grape skins may be gently pressed, and the must then fermented like a white wine.
200
What are the characteristics of a rose made by 'short maceration'? (2)
1. Deeper in colour
| 2. More pronounced in flavour
201
Which areas might you expect to find roses made by 'short maceration'? (2)
1. Spanish roses
| 2. Tavel (Southern Rhone)
202
What is meant by 'Saignee'?
Means 'bleeding' when the rose is a by-product of must concentration in red wine production.
203
Explain 'Blending' in rose production.
Involves blending a small proportion of red wine with a much larger volume of white white, and it retains the aromas and flavours of the white grape.
204
Which grape & area might you expect to find roses made by blending?
New Zealand, Sauvignon Blanc
| Champagne and their varieties!
205
What are the advantages and disadvantages of blending in rose production?
Adv = simple, cheap, the shade of the final rose is much easier to control (colour is vitally important in rose sales).
Dis = lowers quality, not allowed in many geographical indications within Europe.
206
What temperatures are rose wines usually fermented at, and in what vessel? (2)
```
Cool temperatures (between 12-16'C)
Stainless steel tanks
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207
For roses that are good to outstanding quality, what would you expect the growing conditions to be like, and why? (2)
1. Cool or moderate regions or sites (medium to high levels of acidity, low to medium levels of alcohol)
2. Picked early to retain fresh fruit and acidity (in warm regions)
