Viticulture & Vinification Flashcards
1
Q
What decisions does the viticulturist confront? (8)
A
Vine training Pruning methods Canopy management Fertilization Irrigation Harvest dates Disease control Monitors development of vineyard in general
2
Q
What are the 6 stages of a vine’s lifecycle in order?
A
Budbreak Flowering Fruit Set Véraison Harvest Post-Harvest (pruning)
3
Q
Budbreak occurs as the average temperature suprasses what temperature in F? When does this usually occur in the Northern Hemisphere? What is produced during this stage? What marks the end of this stage prior to flowering?
A
50F
Usually occurs in March or April
The first small shoots and leaves will break through the buds
The formation of small green clusters called embryo bunches form marking the end of budbreak and beginning of flowering
4
Q
During budbreak the vine is most susceptible to what vineyard hazard?
A
Frost
5
Q
When does flowering typically occur in relation to budbreak? What three hazards is the vine most susceptible at this point?
A
Occurs 6-13 weeks after the initial budbreak depending on the climate
Damaging effects of cold, frost, and wind
6
Q
What stage follows flowering? What is each grape the product of during this?
A
Fruit Set follows flowering
Each grape is the product of individual fertilization
7
Q
What percentage of embryos achieve fruit set? What happens to the rest? What happens to the fruit during this stage leading up to veraison?
A
around 30%
The rest “shatter” falling from the cluster.
The berries enlarge through July and remain hard, high in acidity and low in sugar leading up to véraison
8
Q
When does veraison typically occur in the northern hemisphere? What happens to the grapes? Does this happen to all grapes on a cluster uniformly?
A
Typically begins in August
Sugars are moved from the leaf system into the fruit and the grapes soften and change color.
This does not happen uniformly and uneven ripening is not uncommon.
9
Q
Which grape is notorious for ripening unevenly?
A
Zinfandel
10
Q
In addition to the grapes ripening, what else ripens in tandem?
A
Cane ripening occurs in tandem with grape ripening.
11
Q
When are grapes ready for harvest? When does this begin at its earliest? Latest?
A
When the grapes have achieved the optimal balance of sugar and acid they are ready for harvest.
Begins as early as late August and may last through the beginning of November in cooler climates.
12
Q
Which grapes are generally harvested first, red or white?
A
Whites are generally harvested first.
13
Q
What does phenolic ripeness refer to?
A
Ripeness of tannin and seed lignification
14
Q
After harvest what happens to the vines?
A
They lose their leaves and enter a period of winter dormancy
Fertilizer may be applied in the fall after harvest, and the vines will be pruned over in the winter to prepare them for next year’s growth.
15
Q
What is the difference between climate and weather?
A
Climate encompasses expected temperature, rainfall, sunshine, wind, and other atmospheric elements, and remains stable form year to year
Weather is the daily manifestation of climate and generally responsible for vintage variation.
16
Q
For temperature, what does the vine prefer as a mean annual range in F? What summer temperature do grapevines require on average to successfully ripen red grapes? White grapes? What parallels does this generally restrict viticulture to?
A
Prefers a mean range of 50-68F with an ideal temp of 57 F
Red grapes require an average temp of 70F
Whites require an average temp of 66 F
17
Q
What is the California Heat Summation Index?
Sometimes known as the Winkler scale
A
Method for classifying climates solely by temperature
18
Q
How are degree days calculated for the California Heat Summation Index (Winkler Scale)?
A
Calculated by multiplying the days in each month of the growing season (April 1-October 30) by the mean number of degrees over 50 F for that month. The months’ totals are then added up to come up with the number of degree days.
19
Q
What are the six Regions for the CHSI and what are their corresponding degree day value ranges?
A
Region Ia (1500-2000) Region Ib (2000-2500) Region II (2500-3000) Region III (3000-3500) Region IV (3500-4000) Region V (4000-4900)
20
Q
What is the minimum amount of sunshine required to support viticulture in hours?
A
Approximately 1300 hours
21
Q
Sunshine during the growing season (increases/decreases) the further one moves away from the equator.
A
Increases the further you move away from the equator.
22
Q
How much annual rainfall does a vine require to produce an adequate crop?
A
20-30 inches annually
23
Q
When do Mediterranean climates receive most rainfall seasonally?
A
Winter and spring
24
Q
What happens when too little rain is received by the vine? How does this affect berry size and ripening?
A
Water stress will occur and this promotes smaller berry size, too much stress and the vine will shut down interrupting ripening.
25
How does too much rain affect the vine?
The vine itself will not be adversely affected but the berries will dilute the fruit and create a friendly environment for fungal diseases
26
In what ways does wind adversely affect the vine? How does it provide benefits to the vine?
When its extreme it can undermine flowering and denude vines. In colder climates the chill can be devastating
Provides benefit in the form of serving as detriment to mold and mildew.
27
Describe the differences between Macroclimate, Mesoclimate, and Microclimate in regards to what each refers to.
Macroclimate refers to larger areas of a region
Mesoclimate refers to the climates within a vineyard
Microclimate refers to to the climate in and around the vine canopy and restricted space including all parts of the vine above the ground
28
What does well-drained soils encourage in regards to vine growth?
Encourages the vine to dig deeply for water and minerals
29
What does high soil pH like that found in limestone-rich soils encourage in the grapes?
Higher acidity in the grapes (lower pH)
30
How can acidic soil, that with a low pH, be treated?
Applications of lime can reduce the effects of low pH
31
Clones are identical genetic reproductions of a single vine and are selected for a host of different attributes in both the field and the wine. Name 5 attributes commonly selected for.
```
Disease resistance
Hardiness
Yield
Aromatics
Structure
Color
```
32
Other than colonal selection, what other method for propogating the vine exists? How does it work and what does it promote in the vineyard?
Selection Massale - Budwood from a number of vines throughout the vineyard is selected for replanting. This promotes broader genetic diversity of the vineyard and thus more complexity in the wines.
33
What is the most common rootstock which vinifera grapes are grafted on to protect the vine from phylloxera?
Vitis Riparia
34
In addition to resistance to phylloxera, what other three traits are considered when selecting a rootstock?
Ability to withstand diseases and drought
Tolerance to salt and lime
Effect on Vine Vigor
35
In many European appellations a newly planted vine must not be used for production until it’s at least how many years old? By what year is the grapevine considered mature? What stabilizes for the vine at this time?
At least three years old
By the 6th year the grapevine is considered mature, shoot growth and the vine's annual yield stabilizes at maturity
36
How old does a vine have to be for its root system to be considered mature?
Root system will be mature for a vine at 10 years of age.
37
After how many years will the yield of the vine begin to decline?
After 20 Years
38
Vine Training encompasses what three practices for the vine? What’s the objective?
Pruning, Shaping, and Trellising
The objective is to maximize the vine's performance in local conditions and to keep its canes from touching the ground and establishing new roots.
39
What is a cane?
The product of a green shoot (fruiting cane) hardening to become a woody extension.
40
What are buds?
Point along the cane that produce a shoot during the spring.
41
What is a spur?
A spur is a cane cut back to two buds
42
What are the two most common vine training techniques?
Head-training
| Cordon-training
43
How can head-trained vines be pruned?
Spur-pruned
| Cane-pruned
44
How are cordon-trained vines pruned?
Spur-pruned
45
What are the two essential methods of pruning?
Spur-pruning
| Cane-Pruning
46
Guyot and Gobelet are pruning techniques for what kind of training method? Which uses cane-pruning? Which uses spur-pruning?
Head-training
Guyot uses cane-pruning
Goblet uses spur-pruning
47
What are Gobelet-pruned vines called in Spain? Italy? Australia?
En vaso (Spain)
Albarello (Italy)
Bush (Australia)
48
Cordon de Royat and Geneva are examples of what kind of training? Which is most similar to Guyot? How is it different than Guyot?
Cordon-training
Cordon de Royat is most similar to Guyot, but there's a single spur-pruned permanent cordon extending from the trunk rather than a two year-old cane
49
What are the four categories of disease a vine may be subject to?
Fungal
Bacterial
Viral
Phytoplasmic
50
Fungal diseases are manifested as what two things? What climates are these most prevalent in? What parts of the vine do they typically affect the most? How can they be controlled?
Mildew or Mold
Warm and damp climates are most conducive to these
Typically affect the root system or the canopy
Can be controlled through application of fungicide spray and other applications
51
How do viral diseases infect the vine? Cure?
Viral diseases spread through grafting or transmission by insects
There is no known cure for many common viral infections, but they can be partially controlled by removal of appropriate sections of the vine for propagation of new, healthy vines.
52
Which is more devastating usually, bacterial or viral disease?
Bacterial
53
How are phytoplasma diseases introduced to the vine?
Caused by phytoplasmas, pathogens similar to bacteria, but symptomatically similar to viral diseases, and like viruses must spread through an insect vector or rootstock grafting.
54
What is Daktulosphaira vitifoliae? How does it affect the vine? How are vines protected from this? What major wine producing country is the only one that is totally free from this?
Phylloxera
Feeds on the roots of the vine destroying the root system
Vines are grafted onto American rootstock such as Vitus riparia to prevent phylloxera's effect
Chile
55
Powdery Mildew, Downy Mildew, Esca, Bunch Rot, Eutypa Dieback, and Black Rot are known as what kind of diseases?
Fungal Diseases
56
Oidium (Uncinula necator) is also known as what in the vineyard? What parts of the vine does it affect? How does timing of infection in relation to the vine’s growth cycle influence these effects? How is it controlled and/or prevented?
Powdery Mildew
Affects all green parts of the plant, marking grapes, leaves, and shoots with dusty white mildew growth
If infected prior to flowering, yields will be reduced
If infected after fruit set, berries will struggle to achieve veraison and reach full size
Application of sulfur and other fungicides is used for control and prevention
57
Peronospora is also known as what? What is the agent of this disease? How does this disease affect the vine? What symptom is visible when vines are infected with this? Where is it least likely to be a threat? How does the fungus survive the winter? How is the fungus treated?
Downy Mildew
Plasmopara viticola is the agent of the disease and it affects the green portions of the vine, causing leaves to drop off the vine which limits the vine's ability to photosynthesize
The infection is first visible as an oil spot on the leaves. It then develops as a white, cottony growth on the underside of the leaves. Arid regions are the least likely to be affected by this. Treated with Bordeaux Mixture
58
Dead Arm is also known as what? It is caused by what fungus? How is it introduced to the vine? Where is it most common? (climate)
Eutypa Dieback
Caused by Eutypa lata fungus whose spores are varied by rain and enter the vine through pruning wounds
Most common in Mediterranean climates.
59
How does Eutypa Dieback affect the vine?
Stunts shoot growth as the fungus releases its toxins, and eventually the infected cane may die (dead arm)
Has a drastic effect on yield, but does not devalue the quality of the crop.
60
Phomopsis viticola manifests as a similar disease to what fungal disease?
Eutypa Dieback
61
Esca (Black Measles) thrives in what kind of climate? How is it unlike other fungal diseases in regards to method of infection? How is it exacerbated? Spread?
Thrives in warmer climates but exists worldwide, no known control or cure
Esca is different than other fungal diseases in that it is a result of a complex of fungi, rather than a single organism
Young Vines: the disease will weaken growth, affect berry development and discolor leaves, in hot-weather an infected young vine may suddenly die
Older Vines: affects the wood, causing the interior of the trunk and arms to soften and rot from the inside (condition that caused Romans to use affected vines for firewood)
Disease is exacerbated by rainfall, and can be spread by wind or on the infected sheers of careless vineyard workers
62
How does Esca affect younger vines? Older vines? What’s the lifespan of Esca-infected vines? What’s the cure?
Young Vines: the disease will weaken growth, affect berry development and discolor leaves, in hot-weather an infected young vine may suddenly die
Older Vines: affects the wood, causing the interior of the trunk and arms to soften and rot from the inside (condition that caused Romans to use affected vines for firewood)
Lifespan: Esca infected vines rarely live past 30 years of age
No known control of cure
63
What is caused by the Guignardia bidwelli fungus? How does the disease produced by this fungus affect the vine? What’s the symptom? How can it be controlled?
Black Rot
Disastrous Yield reductions are the effect
Symptoms: Originates as black spots on the vine's shoots, leaves and berries
Fungicide sprays can control it.
64
What are the two most common forms of bunch rot and how do they affect vine?
Grey Rot - Breaks down the skins of grapes and allows other yeasts and bacteria to rot the grapes
Noble Rot - Grape skins are broken down and the fungus dehydrates the grapes with no further detriment to the grape when humidity is at least 90% and the weather is warm.
65
Pierce’s Disease and Crown Gall (Black Knot) are known as what kind of disease?
Bacterial Disease
66
What is Xylella fastidiosa? How is it transmitted? Where is it most common?
The bacterial agent that causes Pierce's disease
Transmitted by the glassy-winged sharpshooter (a leafhopping insect found near citrus orchards and oleander plant
Most common in the Southern United States and Mexico
67
How does Pierce’s Disease affect the vine? Is there a cure? What’s the prognosis?
A scourge, renders vines incapable of producing chlorophyll and kills the vine within one to five years.
There is neither a cure, nor a chemical control for the disease
68
Agrobacterium tumefaciens causes what bacterial disease? How is the disease spread? Where is it most common climate-wise?
Crown Gall (Black Knot)
Disease spreads when trunk ruptures in the winter. Bacteria invade the outer trunk and rapidly multiply
The disease spreads through the propagation of infected budwood
Thrives in cooler climates.
69
Xanthomonas ampelina causes what bacterial disease? How does this affect the vine? How can it be treated?
Bacterial Blight
Kills young grapevine shoots
Spread by rain and compromised pruning tools
Can be controlled by hot water treatments and copper sprays such as Bordeaux Mixture.
70
Leafroll and Fanleaf Degeneration are classified as what kind of disease? Which is responsible for as much as 60% of the world’s grape production loss?
Viral
Leafroll Virus is responsible for as much as 60% of the world's grape production losses.
71
The mealy bug is notorious for spreading what viral disease? What are the symptoms of this disease? How does it affect the vine?
Leafroll Virus
Affected vines display radiant shades of red and gold in the autumn
Reduces yields and delays ripening.
72
Nematodes are notorious for spreading what viral disease? How do they transmit this disease? What are the effects of this disease on the vine?
Fanleaf Degeneration
Transmission through feeding by nematodes on infected roots and then feeding on unaffected roots.
Effects are severely curtailed yields and affected vines must be removed. A complex of similar diseases, Fanleaf degeneration deforms shoot growth, leads to poor fruit set and shot (seedless) berries
73
What are the symptoms exhibited on a vine infected with Fanleaf Degeneration?
Leaves on infected vines are malformed, resembling fans in appearance, and may form yellow bands around the veins.
74
Flavescence Dorée is an example of what kind of disease? How is it spread? What’s the cure?
Phytoplasmic
Form of grapevine yellows, first appeared in Armagnac in 1949
Spread by leafhopper insects and propagation of infected vines
No cure, although insecticides may be used to control leafhopper insect populations an mitigate its spread
75
How does Flavescence Dorée affect the vine?
Initially delays budbreak and slows shoot growth, eventually causing bunches to fall off of the vine and berries to shrivel. Will discolor leaves, and causes pustules and cracks to form and may kill young vines.
76
What’s the major drawback from the production of chemical fertilizers?
The high inputs of (fossil fuel) energy
77
What is the central goal behind sustainable viticulture?
To return the vineyard to a self-sustaining position in harmony with a larger ecosystem to which it belongs.
78
What does Organic farming prohibit? What treatment is allowed?
Synthetic chemical treatments
Bordeaux Mixture is allowed (even as copper levels build with repeated usage!)
79
What is Bordeaux Mixture composed of? What is its most common use?
Copper sulfate and calcium oxide
Most commonly used as a fungicide.
80
If a bottle is produced from organically-grown fruit but uses SO2 for preservative purposes what will the label likely say in reference to its organic ties?
"wine made from organically grown grapes"
81
If a wine is labeled Organic, what is prohibited from being added following fermentation?
No added sulfites
82
Which farming practice is typically utilized as an approach to weed, insect, and disease problems that tolerates application of some synthetic products, but limits their use overall? Hint: often utilized as a vineyard transitions from conventional to organic viticulture.
Integrated Pest Management (IPM)
83
Who is responsible for regulating and certifying farms as biodynamic?
Demeter
84
VINEA is located where?
Walla Walla Valley, Washington
85
A wine may carry the designation “Oregon Sustainable Certified Wine” if it is produced by a minimum of what % fruit certified by Salmon-Safe?
97%
86
What is the essential formula of alcoholic fermentation?
yeast + sugar = ethyl alcohol and CO2
87
What are the five most common byproducts of fermentation?
Traces of volatile compounds that include:
```
Acetaldehydes
Ethyl acetate
Sulfur dioxide (SO2)
Hydrogen Sulfide (H2S)
Fusel Oils
```
88
Which byproduct of fermentation will exist in trace amounts due to it being the last link on the chain of intermediate compounds between sugar and alcohol, but is regarded as a sign of oxidation in finished wines?
Acetaldehydes
89
What byproduct from fermentation is created by conversion from remaining acetaldehyde into acetic acid and subsequent reaction with oxygen and is considered a fault? What is it known as?
Ethyl acetate
Volatile acidity
90
What byproduct of fermentation is created by yeast when low levels of nitrogen are present in fermenting must? What is this known as?
Hydrogen Sulfide
Reduction
91
What are the benefits of using cultured yeasts for fermentation?
Cultured yeasts promise reliability, and are often able to continue to work in higher levels of alcohol than ambient yeasts.
92
What is the benefit of using Ambient Yeast for fermentation? The drawback? What are these yeasts often inaccurately identified as?
Creates a more complex wine
Drawback is they are by nature less predictable though
Often inaccurately identified as native or wild yeast
93
How are ambient yeast eliminated in a fermenting must?
Inoculation of cultured yeast with use of SO2 in tandem.
94
The amount of heat generated by fermentation and thus the speed of fermentation increases with what in relation to the vessel?
Amount of heat generated by fermentation increases with the size of the must so the larger the vessel used.
95
How does barrel usage for maturation affect the wine?
Allows gentle, slow oxidation to occur, rounding out and softening the texture of the wine.
96
What two factors in regards to barrel usage affect the flavor the most?
The level of toasting and the type of the wood used.
97
The process of making a barrel requires heat and this process has three stages. What are they and what is the French name for each?
Warming (chauffage)
Shaping (cintrage)
Toasting (bousinage)
98
The levels of what two things rises as the level of toasting increases?
The level of lactones and vanillin rise with increasing toasting levels
99
What kind of toasting promotes the most extraction of wood tannin?
Light toasting
100
Quercus robur and Quercus petraea are examples of what kind of wood?
French Oak
101
How is wood for French oak barrels processed differently than wood for American oak barrels? Which oak trees grow faster? Which have a tighter grain?
French oak is split rather than sawn and air-dried, a technique that leaches out some of the oak's more aggressive tannins and flavors.
American oak is sawn, which results in more vanillin, lactones, and coconut in the wines. American oak is also quickly kiln-dried and lactones are concentrated
French oak has a tighter grain.
102
Most of a barrel’s flavor is transmitted to wine in what year of its usage?
1st year
103
What effect on wine does the oak chips alternative lack that real new oak aging give?
The ability to gently oxygenate the wine for texture.
104
What two things does Chaptalization provide more of in the finished wine?
Increases final alcohol and glycerin content of the wine.
105
In what kind of climate is Reverse Osmosis most common?
Warmer climates of the new world where excessive ripening leads to high alcohol levels in the finished wines
106
De-alcoholization in the EU is legal as of 2009 as long as the alcohol is not adjusted by more than what %?
Not more than 2%
107
Which two acids are the two principal acids used for acidification? Which is preferred for addition prior to fermentation?
Tartaric and malic acid
Tartaric acid is preferred for pre fermentation chaptalization
108
What is microbullage? Where was it first used and for what purpose?
Micro-oxygenation
First used in Madiran to soften the harsh tannins the Tannat grapes are known to produce.
109
At what point of the fermentation process can malo occur? What acid is converted during the process? What is the product? What byproduct is created? How is this expressed in the wine? What does the process contribute to the wine overall?
May take place during and/or after fermentation
Malic acid is converted to lactic acid
The product is softer lactic acids and CO2 which results in rounding out the texture of the wine. Dactyl is also produced as a byproduct and it gives the wine its buttery aromas.
110
What is the difference between Carbonic Maceration and Semi-carbonic maceration?
Carbonic - Grapes are put into an anaerobic environment and blanketed in CO2. This causes intracellular fermentation. Only 2% alcohol can be produced so this must be combined with conventional fermentation to ferment to completion (tank is often sealed for full carbonic)
Semi-Carbonic - Grapes are placed into a vat and the grapes on the bottom are crushed by the weight of the grapes above. This causes natural fermentation to take place giving off CO2 that when in contact with the grapes above initiates intracellular fermentation.
111
What happens during carbonic maceration? How many degrees of alcohol are typically created before the berries cease intracellular fermentation?
Intracellular fermentation
2% alcohol
112
Below and above what temperature extremes will yeasts not act?
Below 50F most yeast will not act
Above 113F most yeast will die
113
Why are white wines typically fermented at cooler temperatures and red wines at higher temperatures?
Cooler fermentations preserve freshness and fruit flavor in white wines
Red wines are fermented at higher temperatures for the purpose of higher extraction of color, tannin, and flavor compounds.
114
Stuck fermentations will typically occur at what temperature F? What is the risk involved with this?
95F and above
Volatilized (lost) flavor compounds are the risk associated with this
115
What is MOG? What are jacks? When are they displaced?
Material Other than Grapes (MOG)
Leftover pieces of grape stem (Jacks)
They are displaced after destemming
116
What does whole berry fermentation encourage? What grapes are commonly fermented in this manner?
Encourages a level of carbonic maceration (common with Pinot Noir and Syrah)
117
What is the purpose of pre-fermentation maceration/cold soak? What’s the difference?
Promotes extraction of color and tannins
Cold Soak lasts much longer and requires addition of SO2 under cool temps, purposeful extraction
Pre-fermentation maceration was traditionally the consequence of waiting for ambient yeasts to ignite fermentation.
118
What is common practice prior to fermentation in order to achieve a greater skins to juice ratio? What does this promote?
Saignée
Promotes more extraction
119
Why are grape skins always present during fermentations of red wine?
Phenolics contained in the grape skins - tannin, color compounds (anthocyanin), and flavor compounds - are extracted from skins during fermentation
120
What is the chapeau? What is pomace? What causes this to surface to the top of fermenting red wine? What happens if this is not managed?
Chapeau is a cap of grape solids (pomace) that develops on the surface of the must pushed up by CO2 during fermentation. The cap will dry out, solidify and prevent extraction.
121
Pigeage, Remontage, and Délestage are all methods for managing the cap during red wine fermentation. Describe how they’re different by discussing how they work.
Pigeage is punching down manually by workers using poles, paddles, or even their own feet. Now often done mechanically
Remontage is pumping over, fermenting juice is pumped over the cap aerating the wine and promoting a healthy yeast culture
Délestage is fully draining the fermentation vessel and racking the wine into a separate vessel while the cap drains fully. The wine is then pumped back over the cap in the fermentation vessel.
122
What kind of wines will undergo post-fermentation macerations? For how long does this last? Where is this most common?
Wines of great structure like Nebbiolo
This can last for a period of days or weeks before pressing off the skins occurs.
Piedmont - Barolo / Barbaresco
123
After fermentation and post-fermentatoin maceration the wine is removed from the vessel in the form of vin de goutte and vin de presse. What is the difference between these two?
Vin de Goutte (free run) - high quality juice derived without pressing
Vin de Presse (press wine) - lesser quality juice with more tannin, usually blended into top wines for added structure or reserved for lesser wines.
124
What is soutirage? When is this employed? What does it provide for the wine?
Soutirage is also known as racking. Usually employed during the maturation process of the wine (tirage), provides aeration and aids in clarification as the wine is removed from its lees, or sediment
125
When does Malolactic fermentation occur in red wine production?
Occurs quickly at the end of red wine fermentation or slowly during maturation.
126
When is SO2 added to wine following fermentation? If no sulfur is added what may appear on the label?
During maturation or just before bottling
"sans soufre"
127
Bentonite, casein, isinglass, gelatin, and egg whites are commonly used in the process of what? Which is the most vegan-friendly?
Fining
Bentonite is the most vegan friendly as it is clay not the product of a living animal.
128
For white wine production, pre-fermentation maceration lasts for how long compared to days for red wine production?
Usually occurs over a period of hours for white wines rather than days for reds.
129
What does maceration pelliculaire contribute to white wines that is encouraged? What’s the drawback?
Encourages extraction of aromatic compounds, but may lead to excessive tannin and bitterness in the final wine if unchecked.
130
What is the French word for “settling” following fermentation?
Débourbage
131
What is the purpose of cold stabilization following fermentation of white wines? At what temperature does this process achieve its purpose?
Causes tartrate crystals to precipitate out of the wine at a temperature of approximately 25F
132
How is residual sugar preserved in white wines? What process is necessary to preserve the integrity of this wine and ensure that the remaining sugar is not metabolized into alcohol?
Arrested fermentation or the addition of sterilized fresh grape juice following fermentation. Filtration of leftover yeast out of the wine is necessary to prevent unwanted refermentation in the bottle.
133
Lees contact in white wine making encourages what process? Why?
Malolactic fermentation. The lactic acid bacteria feed on the nutrients in lees.
134
White wines matured in oak, such as the classic wines of Burgundy and Graves are typically bottled after how many months?
9-18 months
135
Below what level of wine quality in the EU is blending for the purposes of making rosé illegal? Hint: it doesn’t make sense
Below PGI level
136
What is the name of the method for creating rosé that is really a byproduct of concentrating the must for a red wine fermentation? Hint: bleeding
Saignée
137
What is the difference between vin gris and saignée?
Vin gris refers to a style of wine making wherein red grapes are fermented in the nature of white grapes. In other words the grapes are crushed and pressed off of their skins immediately following and then fermented. Due to the color of the skins a slight pink tinge is present in the final wine
Saignée is the byproduct of bleeding off juice for red wine fermentation for the purpose of promoting higher extraction in the red wine. The juice bled off is fermented and the product has a darker color. Essentially both are processes of making rosé but vary in the amount of time the wine has seen skin contact.
138
What is the difference between millerandage and coulure? How does each affect the vine? Which is commonly called "hens and chicks" or "pumpkins and peas"?
Millerandage is uneven ripening due largely to cool, rainy or otherwise bad weather during the flowering stage. A.K.A "hens and chicks" or "pumpkins and peas"
Coulure refers to the failure of a grape to fertilize resulting in "shatter" this can cause grape bunches to be less compact and promote a friendly environment for grape diseases.
