Brainscape's Knowledge GenomeTM

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


See full index

WSET Sparkling Wine > Viticulture/Wine Making > Flashcards

Viticulture/Wine Making Flashcards

You may prefer our related Brainscape-certified flashcards:
WSET ® Level 1 Spirits flashcards Introductory Sommelier Exam (CMS) flashcards WSET ® Level 3 Spirits flashcards WSET ® Level 2 Wine flashcards WSET ® Level 1 Wine flashcards WSET ® Level 3 Wine flashcards Wine Appreciation flashcards WSET ® Level 2 Spirits flashcards WSET® Level 4 Wine flashcards
1
Q

below about what temperature is the vine dormant

A

10C

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

3 ways temperature affects yield

A

1) vigour of the vines
2) number of flower clusters produced and their size
3) Success of the setting of these flowers into berries

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

3 ways temperature affects quality of crop

A

1) level of yield
2) accumulation of sugars/reduction of acids
3) development of wine aromas and their precursors

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

frost damage to vinifera at which temperature

A

starts at -15C, is serious at -20C, and fatal at -25C. Site usually unsuitable for viticulture if temp falls below -20C more than once every 20 years or if mean temp is below -1C during coldest month

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

Amerine and Winkler’s Heat Summation System measures Growing Degree Days (GDD)

A

subtract 10C from from mean temperature of the month and multiply result by number of days in month. Sums are totaled for each of the seven months of the growing season

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

EU zone A

Germany (excluding Baden), UK

A

min% abv - 5%
max enrichment +3.5% to 11.5% (to 12% for reds)
acid adjustment -1 - 0 g/L

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

EU zone B

Loire, Champagne, Alsace, Austria

A

min% abv - 6%
max enrichment +2.5% to 12% (12.5% for reds)
acid adjustment -1 - 0 g/L

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

EU zone C 1a

Bordeaux, SW France, Rhone, Vinho Verde

A

min% abv - 7.5%
max enrichment +2% to 12.5%
acid adjustment -1 - 0 g/L

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

EU zone C 1b

Hungary, Trentino-Alto Adige

A

min% abv - 8%
max enrichment +2% to 12.5%
acid adjustment -1 - 0 g/L

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

EU zone C 2

Languedoc-Roussillon, Provence, Northern Spain (except Atlantic Coast), Most of Italy

A

min% abv - 8.5%
max enrichment +2% to 13%
acid adjustment -1 - +2.5 g/L

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

EU zone C 3a

Parts of Greece

A

min% abv - 9%
max enrichment +2% to 13.5%
acid adjustment 0 - +2.5 g/L

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

EU zone C 3b

Portugal (except Vinho Verde), Southern Spain, Puglia, Sicily, Most of Greece

A

min% abv - 9%
max enrichment +2% to 13.5%
acid adjustment 0 - +2.5 g/L

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

How much water does vine need per growing season

A

500mm/year or equivalent in irrigation (cool climate)

as much as 750mm/year or equivalent in irrigation (hotter climates)

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

1mm of rainfall on one square meter

A

1 litre

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

affect of sunlight on vine growth

A

1) indirect effect due to heat accumulation
2) direct effect on bud viability, the initiation of vine flowers, berry ripening, cane maturation
3) direct effect on the rate of photosynthesis

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

Amount of sugar in grapes depends on

A

balance between amount of sugar created through photosynthesis (which increases with sunlight but not temperature) and the vine’s other metabolic needs (which increase with temperature)

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

mean temperature increase with elevation

A

0.6C with every 100 meter rise about sea level corresponding with a heat summation reduction of about 105 degree-days/year

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

particles in soil graded according to diameter (in mm)

A

0, clay, 0.002, silt, 0.02, fine sand, 0.2, sand, 2 gravel - 2+

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

loam

A

balanced mixture of clay, silt, and sand

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

limestone

A

sedimentary rock formed from deposition of shells and skeletons of marine animals. Consists of Calcium Carbonate is usually alkaline and free-draining

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

chalk

A

formed like limestone but has a lower density and is more free draining found in Champagne and Jerez

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

dolomite

A

similar to limestone but with high levels of magnesium

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

sandstone

A

made up of compressed sand (quartz)

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

shale

A

sedimentary rock originally composed of clay and is very soft

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

slate

A

shale that has been metamorphosised. ls harder and less porous than shale

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

granite

A

extremely hard and dense but still free draining

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

N

A

major constituent of cell proteins, nucleic acids, chlorophyll, and hormones. 2nd only to water in importance for plant growth

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

P

A

a key element in energy fixation. encourages root growth and ripening

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

K

A

regulates the flow of water and sugar in the plant which encourages ripening

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

Ca

A

regulates cell acidity and is an important component of cell walls

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

S

A

an essential constituent of some amino acids and enzymes

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

Mg

A

and essential component of chlorophyll, regulates internal acidity, sugar metabolism, encourages ripening

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

petiole

A

leaf stalk

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

floral initiation

A

embryonic flowers develop in the dormant bud the year preceding bud burst. success depends on temperature, sunlight exposure, and sufficient carbohydrate reserves in the wood

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

budburst

A

vines sensitive to late spring frosts at this stage

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

coulure

A

failure of berries to set or fertilize

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

layering

A

vine canes are buried in the ground then separated from the parent plant once established own roots. best way to propagate some species like v. berlandieri and rotundifolia

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

v. labrusca

A

found wild in NE USA. dark berries described as “foxy.” parent of american hybrids such as Concord.

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

v. riparia

A

found wild on river banks in Central-Eastern parts of North America. Surface rooting. Low in vigor. encourages early ripening. good resistance to phylloxera but suffers from chlorosis in chalky soils. sed to control vigor in highly fertile soils

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

chlorosis

A

iron deficiency

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

v. rupestris

A

found in southern center of USA. vigorous and deep rooting. susceptible to chlorosis. good choice of rootstock for poor soils with limited water availability.

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

v. berlandieri

A

grows on chalky slopes in southern USA and Mexico. vigorous and deep rooting. high resistance to chlorosis. poor ability to root so rarely used as a pure species. often hybridized with riparia and rupestris in order to produce lime-resistant rootstocks that graft and root easily with different levels of vigor

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

True/False. v. riparia is low in vigor

A

True

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

This rootstock is resistant to chlorosis

A

v. berlandieri

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

True/False. v. berlandieri has low vigor

A

False

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

True/False. v. riparia is drought resistant

A

False

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

True/False. v. rupestris is drought resistant

A

True

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

True/False. chardonnay is prone to Grey Rot

A

True

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

True/False. Chenin Blanc ripens unevenly

A

True. common to find leafy and tropical aromas in the same wine

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

True/False. Cabernet Sauvignon gives high yields despite low vigor.

A

True

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

Tempranillo can ripen with high levels of malic acid.

A

True. Therefore by-products of MLF are distinctive.

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

Pratylenchus and Meloidogyne

A

species of Nematode that cause damage by feeding off roots

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

Xiphinema Index

A

species of Nematode that spreads viral disease

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

true/false. v. riparia based rootstocks are drought resistant.

A

false. they are however able to tolerate damp conditions

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

v. rupestris will have _____ vigor

A

High

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

v. riparia will have _____ vigor

A

Low

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

True/False. Low vigor rootstocks are usually used in cooler climates.

A

True. They encourage earlier wine production and in quality wine production they can help control yield.

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

Riparia Gloire de Montpellier

A 
very low vigor
humid, cool, fertile soil
Low lime tolerance
Very low drought resistance
Very high phylloxera tolerance
nematode resistant
Suitable for production of quality wines.  Sensitive to compact soils.  Prefers damp conditions.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Rupestris du Lot

A 
Very high vigor
deep, poor, healthy soils
Low lime tolerance
Drought resistant
High phylloxera resistance
Nematode resistant
High vigor mediterranean rootstock.  Sensitive to coulure and compact soils
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

AXR1

A

vinifera x rupestris. offers some of the lime tolerance of vinifera but shows inadequate phylloxera tolerance
High Vigor
suitable in many soil types
High lime tolerance
Moderate drought resistance
Very low phylloxera tolerance
Easy to graft, high yields of quality fruit, but phylloxera a major issue

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

3309 C (Couderc)

A 
riparia x rupestris
Moderate vigor
Cool, fertile, permeable soils
Low lime tolerance
Very low drought resistance
High phylloxera tolerance
high nematode resistance 
Fruits well.  Widely used in France, Germany, Switzerland.  Particularly recommended for acid soils.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

101-14 (Millardet et de Grasset)

A 
riparia x rupestris
Low vigor
Deep, fertile, damp soil
Low lime tolerance
Very low drought resistance
High phylloxera tolerance
Moderate nematode resistance
Suitable for production of quality wines
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Schwarzman

A 
riparia x rupestris
Low vigor
Deep, moist soil
Low lime tolerance
Very low drought resistance
High phylloxera tolerance
Very High nematode resistance
Ideal for areas with serious nematode issues
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

riparia x rupestris

A

halfway between surface and deep rooting. average vigor. Good resistance to phylloxera but poor resistance to chlorosis

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

riparia x berlandieri

A

surface to semi-surface. Good rooting, high resistance to chlorosis. Good affinity with scions and resistance to phylloxera.

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

161 - 49C (Couderc)

A 
riparia x berlandieri
Low vigor
cool, fertile, permeable soil
High lime tolerance
Very low drought resistance
High phylloxera tolerance
Low nematode resistance
widely used in France, Germany, Switzerland.  Good fruiting.  Good for acid soils.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

420A (Millardet et de Grasset)

A 
riparia x berlandieri 
Low vigor
cool, deep, rich, permeable
Moderate lime tolerance
Very low drought resistance
Very high Phylloxera resistance
Moderate nematode resistance
Good for quality vineyards
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

5C (Teleki)

A 
riparia x berlandieri
Moderate vigor
Wide range of soils:  chalky, clay, compact
Moderate Lime tolerance
Very low drought resistance
High phylloxera resistance
High nematode resistance 
Suitable for quality vineyards in northern regions.  Poor (K) uptake.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

5BB (Teleki Selection Kober)

A 
riparia x berlandieri
High vigor
Wide range of soils:  cold, fertile, permeable
Moderate Lime tolerance
Low drought resistance
High phylloxera resistance
high nematode resistance 
Poor uptake of K and Mg.  Not to be used with coulure-sensitive varieties in fertile soil
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

SO4 Selection Oppenheim

A 
riparia x berlandieri
Moderate vigor
Fertile, humid, cold soil
Moderate lime tolerance
Very low drought resistance
High phylloxera resistance
low nematode resistance 
Very fruitful.  Most popular in EU.  Poor uptake of MG --> coulure and stem atrophy.  Several clonal variations available.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

125AA (Kober)

A 
riparia x berlandieri
high vigor
Very wide range of soils
Moderate lime resistance
Moderate drought resistance
High phylloxera resistance 
Moderate nematode resistance 
Not recommended for varieties sensitive to coulure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

berlandieri x rupestris

A

good for planting in dry and stony conditions. Deep or semi-deep rooting systems. Vigorous. Good resistance to chlorosis and drought. Better lime tolerance than straight resistance.

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

99R (Richter)

A 
berlandieri x rupestris
Very high vigor
Prefers soils with average fertility, deep and permeable
Moderate lime tolerance
moderate drought resistance 
Very high phylloxera resistance 
High nematode resistance 
Fruits well.  Used in South of France
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

110R (Richter)

A 
berlandieri x rupestris
very high vigor
deep, poor, clay-calcareous soils
moderate lime tolerance 
high drought resistance
high phylloxera resistance
moderate nematode resistance 
Good rootstock for dry regions.  Poor uptake of K and Manganese
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

140 RU (Ruggieri)

A 
berlandieri x rupestris
Very high vigor
Poor, dry soils
High Lime tolerance
High drought resistance
High phylloxera resistance
Moderate nematode resistance
Suitable for Mediterranean vine growing countries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

1103 P (Paulsen)

A 
berlandieri x rupestris
Very high vigor
Poor dry soils with average compactness
Moderate Lime tolerance
High drought resistance
high phylloxera resistance
moderate nematode resistance
saline resistant warm climate rootstock
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

This rootstock is saline resistant

A

1103 P. berlandieri x rupestris

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

Berlandieri x vinifera

A

good resistance to lime and chlorosis.

some have poor resistance to phylloxera

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

Fercal

A 
berlandieri x rupestris
Moderate vigor
Dry, shallow, calcareous soils
Very high Lime tolerance
High drought resistance
Moderate phylloxera resistance
moderate nematode resistance
Shows Mg deficiency if K applications are too great
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

41B (Millardet et de Grasset)

A 
berlandieri x vinifera
Moderate vigor
Dry, Calcareous soil
High lime tolerance
Moderate drought resistance
low phylloxera resistance
low nematode resistance
used in Champagne and Charentes.  some susceptibility to phylloxera.  Good fruiting, good uptake of Mg.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

This rootstock has good uptake of Mg

A

41B

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

333EM (Ecole de Montpellier)

A 
berlandieri x vinifera
Moderate vigor
humid, compact soils
High lime tolerance
High drought resistance
High phylloxera resistance 
Low nematode resistance
Used in Champagne, Charentes, Midi.  can cause coulure.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

Vitis Champini

A

Important for regions with severe nematode problems, but tends to be extremely vigorous, and unsuitable for high quality grapes

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

Dog Ridge

A 
Vitis Champini
Very high vigor
Poor, light textured soils
Low lime tolerance
Low drought resistance
Low phylloxera resistance 
Very high nematode resistance
For use in regions with serious nematode problems, but with lower quality potential than Schwarzman, and weak phylloxera tolerance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

High density planting often increases or decreases the total effective leaf area

A

increases

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

balance between vine’s root system and its canopy is determined by:

A

vigor of the vine, planting density, fertility of the soil, and the training system

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

main drawback of single wire trellis system

A

shoots often hang down offering no protection to the fruit from sunburn

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

VSP

A

non-divided canopy. adopted in places where there is a high risk of fungal disease in order to keep foliage ff the ground and to simplify spraying and trimming operations

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

cane-pruning and spur-pruning poduce

A

uniformly trained shoots where all the fruit is in one zone and the shoot tips are in another.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

main disadvantage of VSP

A

shoot density is normally high therefore prone to shade. unsuited to high vigor varieties and to high potential sites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

divided canopies (either vertically or horizontally) provide

A

less shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

Scott-Henry

A

Vertical, divided trellis system.

Head trained, Cane-pruned

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

Smart-Dyson

A

Vertical, divided trellis system
Cordon trained, Spur-pruned
upward and downward pointing spurs create two canopies
can be machine pruned

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

head training

A

trunk has a definite head or knob consisting or old wood rather than arms of a cordon. normally subject to cane pruning but may, after spur pruning, be Gobelet. Guyot is a common cane-pruned form of head training.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

cordon training

A

trunk terminates in a cordon and is normally subject to spur pruning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

cane pruning

A

form of winter pruning in which buds are retained on canes including 6-15 buds. usually takes longer to perform by hand than spur-pruning. cane pruning is typical for for vines which have fewer fruitful buds at the base of the canes. cane pruning cannot be mechanized

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

spur pruning

A

form of winter pruning where canes are cut back to two-bud spurs. advantages are it takes less time to prune manually and can be easily mechanized

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

GDC

A

horizontally divided trellis with shoots trained downward. downward pointing shoots expose fruit and basal bud to greater amounts of sunlight. normally mechanically spur pruned and mechanically harvested. downward shoots also shown to devigorate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

U-shaped or Lyre

A

horizontally divided trellis with shoots trained upward in two curtains. very high cost of construction and maintenance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

Prior to planting soil pH should be increased to over ____

A

6.5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

3 soils additions that raise soil pH

A

Calcite (Calcium Carbonate), Magnesite (Magnesium Carbonate), or Dolomite (a combination of both)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

Guyot

A

replacement cane-pruned system with one or more spurs. The cane buds grow into shoots that can be used as canes the following year. The spur buds produce shoots that can be used as canes the following year thus preventing the vine from sprawling too far along the trellis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

main advantage and disadvantage of replacement cane pruning

A

advantage: by limiting the carbohydrate reserves the vine’s vigor is kept under control
disadvantage: requires great skill cannot be mechanized

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

main advantage and disadvantage of of cordon/spur pruning

A

advantage: easier to prune and pruning can be mechanized. retain large volume of permanent wood which can provide carbs (important if budburst occurs while frost is still a risk)
disadvantage: vines are more vigorous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

bud-rubbing

A

removal of a potentially undesirable shoot before it has a chance to grow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

leaf stripping

A

done between veraison and harvest to improve canopy microclimate, allow spray penetration, speed manual harvesting. Can take up to 70hrs/hectare

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

Green Harvesting

A

for established vines alters leaf to fruit ratio, may allow allow conformity with yield restrictions . Usually bunches on laterals and those nearest the shoot tips are removed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

chlorosis

A

yellowing of foliage caused by deficiency of iron, nitrogen, magnesium, and/or sulfur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

Cultivation vs. “no-till cultivation”

A

No-till cultivation is done chemically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

sucrose

A

sugar generated in leaves converted to glucose and fructose in grapes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

enzyme

A

catalyst for reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

resveratrol

A

a phytoalexin, protects plant from fungal disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

planting density

A

way of controlling division of soil resources amongst right number of plants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

partial root drying

A

used to trick vine into allocating resources to fruit ripening rather than vegetative growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

viticulture raisonee (La Lutte Raisonee)

A

‘the reasoned fight’ supported by the Terra Vitis Organization

116
Q

photosynthesis

A

12CO2 + 11H2O –> C12H22O11 + 12O2

117
Q

hydrolysis of scurose

A

C12H22O11 + H20 –> C6H12O6 + C6H12O6

Sucrose + Water –> Glucose + Fructose

118
Q

Sweetness of sugars

A

Fructose, Sucrose, Glucose is the least sweet. Plants prefer Glucose leaving Fructose as the principal sweetener in sweet wines

119
Q

Malic Acid

A

L. Malus = apple.
As the grape matures Malic Acid level diminishes. Because grape consumes malic acid as an energy source, then guconeogenesis

120
Q

Tartaric Acid

A

L. Tartarum = deposit
formed as a byproduct of the synthesis of sugar. main acid in finished wine and unique to grapes. table acid so quantity rises in proportion to sugar production

121
Q

phenolic compounds

A

Non-flavanoids, and flavanoids (polyphenols)

polyphenols can be sub-divided into tannins and anthocyanins

122
Q

non-flavanoids

A

smaller molecules based on benzoic acid and cinnamic acid. influence on flavor relatively minor

123
Q

Hydrogen Sulfide

A

H2S

124
Q

oxidation of alcohol

A

CH3CH2OH + O2 –> CH3COOH + H2O

Ethanol + Oxygen –> Acetic Acid + Water

125
Q

Reductive Taint

A

Sulphur Dioxide becomes chemically reduced to Hydrogen Sulphide

126
Q

Potassium Metabisulphite

A

white powder stable when dry liberates SO2 when wet

used in the vineyard to protect grapes en route to winery

127
Q

CO2

A

cheap and effective antioxidant

but soluble in wine (more soluble at lower temp)
around 800mg/l in whites and pinks important constituent

128
Q

Argon

A

expensive but effective alternative to CO2 and N

129
Q

Dissolved O

A

every molecule of oxygen destroys 4 times its weight of SO2

2SO2 + O2 –> 2SO3
128 32

130
Q

Sparging

A

process of injecting fine bubbles into a liquid usually to remove dissolved oxygen. usually mixture of CO2 and N.

Sparging does not remove oxygen exclusively but will remove anything volatile (flavor components are volatile)

131
Q

Must

A

product of crushing is known as must from Latin Mustum meaning fresh or new.

White wine - Juice
Red wine - Juice + Skins

132
Q

Crushing

A

ripping open grape to allow free-run juice to flow out

optional: crush or leave intact for direct pressing

133
Q

Pressing

A

extraction of juice remaining after crushings

principle of pressing: use minimum pressure required to achieve necessary extraction

134
Q

pectinolytic enzymes

A

releases more juice from the pulp by breaking down gelatinous pectins

135
Q

Draining

A

draining process is slower than other stages and can pose a problem of through-put

136
Q

free-run juice

A

for whites free-run juice is typically between 400 and 500 litres per tonne

137
Q

Pressing the berries

A

pressing comes after juice released from crushing to release remainder of juice (150 to 200 litres per tonne of grapes)

138
Q

basket press

A

vertical screw press

simple and effective. Bed of skins acts as a fine filter yielding juice of good clarity. Presses used for Champagne based on Basket model

issues: cannot be rushed, must exposed to oxygen

139
Q

Horizontal Screw Press

A

Vaslin press
screw is divided into two halves: one right-handed, one left. chains to break up mass of skins

can be completely automated

but juice produced tends to be rather course due to pressure and abrasion of skins due to tumbling action of press

140
Q

Pneumatic Press

A

more efficient pressing at lower pressure

common fault is exposure

141
Q

Tank Press

A

enclosed Pneumatic Press

142
Q

Continuous Screw Press

A

efficient, but produces rough juice

143
Q

Whites: Clarification

A

whites: unfermented must is very susceptible to oxidation almost always protected but SO2 (also to protect from premature fermentation)
exception: hyperoxidation

144
Q

Reds: Clarification

A

red must somewhat impervious to SO2.
red must contains skins which have a high population of microorganisms that cannot be totally controlled by SO2. Some of these organisms produce acetaldehyde which binds with SO2 removing free SO2. SO2 also combines readily with some of the anthocyanins.

Many winemakers use SO2 however because improves extraction of polyphenols

145
Q

Calrification

A

solid particles are nutritious to yeasts because they have become adsorbed to the surface of amino acids, minerals, and vitamins

146
Q

Ways to clarify

A

settling - takes time. SO2 protects must from oxygen and reduces activity of yeasts and bacteria. So temp cooled to below 15C which will slow microbial activity and oxidation. At the same time Oxygen more soluble in cool wine

centrifuging - fast but harsh. exposure is an issue. Can be used at any stage of wineaking

flotation -Can be used for dual purpose of clarification and hyperoxidation by using O rather than N

147
Q

Hyperoxidation

A

counterintuitive: kills more susceptible components of the juice, finished wine is more stable

148
Q

Acidification

A

usually tartaric, citric is cheaper but can be metabolized by some yeasts and converted to acetic,

149
Q

plastering

A

adding plaster or gypsum (Calcium Sulphate). old Jerez practice. Increases acidity by precipitating calcium tartrate and leaving more acidic potassium bisulphate in solution.

more effective to simply add tartartic acid

150
Q

Deacidification

A

add a carbonate
Chalk (calcium carbonate) or potassium carbonate neutralize acids in the must

addition of chalk removes mainly tartaric acid, product is calcium tartrate the crystals of which is difficult to remove being equally soluble at all temps

adding potassium bicarbonate crystals result in potassium bitartrate which is very easy to cold stabalize out

151
Q

double salt deacification

A

calcium tartrate-malate, complex double salt that eliminates both tartaric and malic acids by forming Calcium Tartrate-Malate which is very insoluble.

Does require malic and tartaric acids to be present in roughly equal proportions.

152
Q

vacuum distillation

A

concentrating must by boiling must at very low pressure

153
Q

gaseous nitrogen

A

N2

154
Q

Combined nitrogen

A

in the form of ammonium NH4. N is necessary for the formation of amino acids/proteins within the yeast cell

155
Q

insufficient nitrogen

A

fermentation is reductive, in the absence of nitrogen production of hydrogen sulfide. adding diammonium phosphate or ammonium phosphate up to 1g/litre

156
Q

Thiamine

A

important for growth of yeast populations. allowed to add up to 0.6g/litre

157
Q

Bentonite

A

sometimes added at must state to remove proteins in order to reduce viscosity. another advantage is will remove polyphenoloxidase

158
Q

activated charcoal

A

if white wine must is deeply colored treated with up to 100g/l

159
Q

saccharomyces

A

means sugar-loving

cerevisiae is the most common. It is tolerant of both alcohol and SO2. bayanus associated with sherry production

160
Q

alcoholic fermentation

A

in the absence of oxygen
yeasts + sugars –> alcohol + CO2 +heat

C6H12O6 –> 2C2H5OH + 2CO2
Glucose Ethanol Carbon Dioxide
180 92 88

161
Q

ethanol weight

A

0.7897 g/ml

17g sugar/l produces 1% alcohol by volume

162
Q

temperature

A

extraction of flavor and color components from the skin on one hand, retention of volatile aromatic substances on the other

reds fermented at 20 - 30C (whites at 10 - 18C)

163
Q

ways to stop fermentation

A

1) naturally
2) increase CO2 pressure
3) reduce temperature
4) kill yeasts
5) remove yeasts
6) fortification (results in stable wine)

164
Q

naturally sweet wines

A

factors slowing fermentation

1) shrinking of yeast cell by osmotic pressure (dehydration) due to very high sugar concentration
2) nutrients gradually exhausted

3) botrytised grapes have anti-fungal properties which inhibit alcoholic fermenetation

165
Q

ML

A

wines with very low pH will not undergo ML

Lactobacillus, Leuconostoc, Pediococcus are naturally present in wine and will start spontaneously

Oenococcus oeni can be purchased.

to encourage ML raise temp avoid SO2. Do discourage lower temp add SO2

166
Q

pigeage

A

punching down cap or chapeau

see also pumping-over method

167
Q

submerged cap process

A

screen method, prevents efficient extraction

168
Q

delestage

A

(rack and return). similar to pumping-over

169
Q

rotary fermenters

A

very effective achieves thorough mixing of skins and juice. However serve disturbance can lead to overextraction

170
Q

thermovinification

A

heat crushed mixture to 60-75C for 20 to 30 minutes. Anythoycyanins readily extracted at elevated temperatures.

Beaucastel - after destemming heated rapidly to 90C. Anthocyanins easily extracted. Also destroys the polyphenoloxidase that causes premature oxidation requiring lower dose of sulphur

171
Q

Flash Detente

A

95C for a several minutes then immediately subjected to a low vacuum where the cells are ripped apart

widely used for Cotes du Rhone

172
Q

Carbonic Maceration

A

intracellular followed by extracellular fermentation

anaerobiosis

press juice is of better quality than free run

173
Q

Whole bunch fermentation

A

different styles of Beaujolais are dependent upon length of time the berries are left to macerate. Beaujolais Nouveau is racked off after about one week, whereas higher grade is left up to a month

174
Q

pink wine methods

A

1) short maceration
2) saignee
3) Vin d’une nuit
4) double pasta

175
Q

maceration pelliculaire

A

skin contact particularly useful for aromatic whites

176
Q

batonnage

A

stirring introduces oxygen to the lees which prevents reduction, also increases contact with lees increases leesy flavors

177
Q

Pompe Bicyclette

A

carbonation

178
Q

Fortified Wines

A

according to EU legislation now called “Liqueur Wines”

179
Q

oxidative coupling

A

tannins and anthocyanins interact creating stable coloring matter

180
Q

Quercus Alba

A

American Oak (Penn, Minn, Wisc)

181
Q

Quercus Robur

A

English Oak or Pedunculate Oak.
Limousin is only forest.
Has a coarser grain and a lower aromatic content particularly useful for agin Cognac

182
Q

Quercus Sessilis

A

Found in most French Forests i.e. Troncais, Nevers, Allier, and Vosges.
has a tight grain and is rich in aromatic content

183
Q

Slavonian Oak

A

Quercus Robur

184
Q

IPM

A

focused on timely preventative measures rather than more costly curative ones

185
Q

Botrytis cinerea

A

Grey mold, grey rot, …

heavily infected white grapes will require more SO2, red grapes will require charcoal fining to remove mouldy taint

186
Q

sclerotia

A

botrytis overwinters as sclerotia (hard, dark-brown encrustations of the dormant fungus)

187
Q

bunch rot

A

when botrytis infects flowers can get trapped in center of bunch as grapes expand

188
Q

pre-emergence herbicides

A

become trapped in soil absorbed through roots

189
Q

systematic herbicides

A

absorbed by the leaves

190
Q

contact herbicides

A

‘wilters’ are only temporary for plants with established root systems

191
Q

obsolete botrytis treatments

A

Benzimidazole in the 60s and 70s, then dicarboximides both of which were contact fungicides. Botrytis can become resistant to certain chemicals

192
Q

Scala

A

systematic herbicide for prevention of botrytis. active ingredient pyrimethanil. introduced in 1995. only 3 applications per year but is very effective and has only 7 day harvest interval

193
Q

Sentinel

A

bio-fungicide developed in NZ for preventing botrytis using new strain of predator fungus called Trichoderma harzianum. as effective as other products.

194
Q

Stem rot

A

bortytis infects stems reults in large numbers of bunches to fall to the ground

195
Q

methods to control botrytis

A

1) spraying chemicals

2) open leaf canopy to allow air movement

196
Q

Noble Rot

A

Once grapes reach about 7% potential alc. botrytis affects them differently. grapes must be clean prior

197
Q

Downy Mildew

A

will infect any green part of the vine. Grapes if infected turn leathery and will impart moldy taint to wine. Treated with copper which is particularly effective if used as post-harvest, pre-winter spray to control through dormant period

198
Q

Bordeaux Mixture

A

blend of lime and copper sulphate. Alternatives are copper oxichloride and copper hydroxide which both require less prep and are less likely to persist in the soil

199
Q

Oidium or Powdery Mildew

A

treated with sulphur. Does not require water to transmit air with sufficient moisture is sufficient. Attacks leaves with white powdery covering and causes young berries to split exposing seeds. harvest interval between 21 and 56 days

200
Q

alternatives to sulphur for treatment of Powdery Mildew

A

light mineral oil which is also effective on botrytis, and Strobilurins which are sprays developed from a toad stool called Strobilurus Tenacellus.

201
Q

Anthracnose

A

fungal disease but easily controlled with copper-based sprays

202
Q

Armillaria Root Rot

A

attacks roots, problem in vineyards planted on land that was once wooded. Control is almost impossible. only remedy is to keep land fallow, plow deeply to expose and destroy old tree roots

203
Q

Bacterial Blight

A

only method of control is to remove infect vines and disinfect secateurs before pruning each vine. Copper sprays help

204
Q

Black Rot

A

impossible to eradicate but controlled with copper sprays

205
Q

Crown Gall - Black Knot

A

spread through grafting process. vines become infected following damage to vine after frost has spit trunk. Prevented by Buttage. In New York growers train multiple trunks from base so that if one becomes infected it can be cut off and vine remains productive.

206
Q

Buttage

A

ploughing close to vine so earth is piled up around and over the graft prior to winter.

207
Q

Esca

A

caused by several different fungal pathogens, more common is warm to hot regions. Shows up leaves as light colored areas between veins and necrotic leaf edges, dark speckling will occur on grape. Controlled by keeping vineyard clear of old wood, disinfecting pruning wounds, and avoiding pruning systems with large amounts of permanent wood

208
Q

Eutypa

A

fungal disease caused by Eutypa lata. rarely shows in young vines manifests as malformed, chlorotic leaves. Only control is to avoid systems with a lot of permanent wood, removing old wood and burning, disinfecting wounds with fungicide. Sometimes can rejuvenate infected vines by taking shoots emerging near the ground and completely retraining the trunk

209
Q

Grapevine Yellows - Flavescence Doree

A

group of related diseases caused by phytoplasma (similar to bacteria). Spread by sap-feeding insects and by using material infected in the grafting process. Infected vines have curling yellow leaves.

210
Q

Phomopsis - Dead Arm

A

controlled by copper sprays

211
Q

Pierce’s disease

A

caused by bacterium Xylella fastidiosa spread by various insects

212
Q

Corky Bark

A

Viral. Infected vines have red or red/yellow leaves which tend to curl downward, canes become grooved, areas on the main stems expand and turn corky.

213
Q

Fanleaf Degeneration

A

Viral. Leaves distort and grow in shape of a fan. Then leaves become yellow with yellow veins. Nematodes are vectors

214
Q

Leafroll

A

Viral. rolling of the leaves, slight veining, and color change from green to bronze to red. grapes tend to take longer to ripen and may not achieve sufficient sugar levels

215
Q

Nepoviruses

A

group of 13 viruses spread by nematodes

216
Q

heat treatment of cutting

A

50C for 30 minutes

217
Q

Phosphorous

A

on soils with very low pHs, low P levels may lead to chlorosis-like symptoms

218
Q

Potassium Deficiency

A

Vines deficient in K will show chlorotic leaf margins, often accompanied by cupping of the leaves.

219
Q

Soil Potassium

A

Excess K in soil often associated with high pH in wine. Soils high in K tend to be deficient in Mg

220
Q

Iron

A

Iron is required for chlorophyll production. deficiencies associated with high pH soils

221
Q

Chlorosis

A

high pH soils (7.5 +) fix iron which is required for photosynthesis

222
Q

Coulure

A

poor flowering conditions and/or an imbalance of nutrients

223
Q

Millerandage

A

condition resulting in un-pollinated flowers or very small berries sans seeds

224
Q

Barrique

A

Bordeux. 225 litres

225
Q

Gonci

A

Hungary. 130 litres

226
Q

Micro-Oxygenation

A

main effect is change in polyphenolic structure. best wines for this treatment are high in both tannins and anthocyanins.
two phases: Structuring and harmonisation

227
Q

Ethyl Acetate

A

Principal Ester results from volatile acidity. which is the result of acetobacter. Wines with excess VA smell of varnish because acetic acid forms ethyl acetate

228
Q

VA

A

EU limit for reds is 1.2g/l. EU limits for whites and pinks 1.08g/l. VA becomes noticeable around 0.8g/l. 0.4 to 0.5 g/l is normal.

229
Q

RS

A

mainly fructose because yeasts ferment glucose preferentially. If sucrose was added (i.e. champagne) will have been inverted by acides to equal parts glucose and fructose

230
Q

glycerol

A

major byproduct of fermentation originating from sugar in juice. legs are thought to be due to the surgace tension effect of a combination of glycerol and alcohol. Grapes infected with Botrytis already contain glycerol as a reult of the metabolism of the grape sugars by noble rot + more glycerol from fermentation. Botrytised wines contain a lot of glycerol.

231
Q

Acetaldehyde

A

precursor of ethanol during fermentation also product of its oxidationt

232
Q

yeast bitten

A

wine that has been left in contac for too long with the gross lees is said to be yeast bitten

233
Q

Finingg

A

process of clarification that is used for 2 purposes: 1) to prevent haze, and 2) to remove some of the tannins to improve the balance of the wine

234
Q

Colloids

A

Stabe vs Unstable

Acacia (gum arabic) is a stable colloid used to increase wine stability

235
Q

Ox Blood

A

prohibited in EU since 1987. Active ingredient is Albumin

236
Q

Albumin

A

effective at removing harsh tannins and troublesome colloids

237
Q

Gelatin

A

similar to Albumin in structure and effect.

Used to remove harsh tannins from reds. Used in conjuction with Silica Sol for treating white wine

238
Q

Silica Sol

A

active substance is silicon dioxide which can be produced in both positive and negative colloidal forms. It is often used with gelatin for removing other protective colloids from white wine.
Similar but less effective than Bentonite

239
Q

Casein

A

useful for decolorizing white wines

240
Q

Tannin for fining

A

wood tannins used in conjunction with gelatin precipitate first with the gelatin then bring down colloidal proteins

241
Q

Bentonite

A

Used to remove heat-unstable proteins from white wines, and to clarify must. Not generally used for reds.
No danger of over fining but forms a voluminous deposit from which it is difficult to recover wine. Effective at adsorbing certain proteins and to a limited extent bacteria

242
Q

Egg Whites

A

used in production of fine reds by adsorbing harsh tannins and excess colloids

243
Q

Oenological Tannins

A

will inhibit Laccase activity from botrytis on red grapes

244
Q

Isiglass

A

like Gelatin reacts with excess tannins in harsh, young reds. Can be used to clarify white wines to be bottled without a final polish filtration.
Expensive and derived from animals

245
Q

PVPP

A

used to remove phenolic compounds from whites especially those that are suffering from pinking or browning

246
Q

Charcoal

A

used to remove brown colors and off odors

247
Q

Blue Fining

A

removal of excess iron and copper. Particularly useful for removing copper as this is the

248
Q

Calcium Phytate

A

removes excess iron from red wines by precipitating out as soluble ferric phytate

249
Q

PVI/PVP copolymers

A

plastic meterial absorbs metal ions such as iron and copper

250
Q

Chitin-glucan

A

polysaccharide and fungal resource used as a fining agent. produced from aspergillus niger

251
Q

Chitosan

A

natural polysaccharide produced from aspergillus niger will remove heavy metals (iron, copper, lead, cadmium). Will reduce levels of ochratoxin A.
Will elimate undesireable organisms notably Brettanomyces

252
Q

Super-Saturation

A

tartrate concentration exceeds solubility limit after fermentation because they are less soluble due to the presence of alcohol

253
Q

tartrate crystals

A

form after colloids denature.

254
Q

Cold stabalization

A

potassium bitartrate is much less soluble at low temps so cold stabilization works very well. solubility of calcium tartrate changes very little with temp so cold stabilization works poorly

chill wine to just above freezing (-4C for a wine of 12% alc). Due the protective effect of the colloids, this process only works well if efficient fining process takes place prior

255
Q

Contact Process

A

quicker, cheeper, more effective than cold-stabilization. wine is chilled to 0C, finely ground potassium bitartrate crystals are added at a rate of 4/l and the wine is stirred vigorously for 1 to 2 hours

256
Q

Ion Exchange

A

prevents crystallization by exchanging calcium and magnesium salts for sodium bitartrate which is more soluble

sodium also replaces potassium however. This process is banned in EU

257
Q

Electrodialysis

A

uses selective membranes to allow passage of potassium, calcium, and tartrate ions under the influence of an electric charge.

Very expensive but customizable, reliable, and wine requires very little to no pre-treatment

258
Q

metatartaric acid

A

prevents tartrate crystals by an unknown mechanism. Thought to coat colloids preventing crystallization. Cheap and effective, but unstable gradually reverting to tartaric acid causing even more problems than if had not been used. lasts about 6-18 months. Perfect for Bag in Box

EU limit is 100 mg/l

259
Q

Carboxymethylcellulose

A

similar to metatartaric acid but lasts longer. EU limit is 100 mg/l

260
Q

Mannoproteins

A

wines that mature on lees have greater tartrate stability. this is due to mannoproteins which are released during yeast autolysis.

added to wine day prior to bottling dose of 200 to 250 mg/l. stable and long lasting. Permitted in EU and Argentina. Pending in USA and AUS

261
Q

Sulphurous Acid

A

SO2 + H2O –> H2SO3

262
Q

Potassium Metabisulphite

A

K2S2O5

releases 57% of its weight when dissolved in acid aqueous solution

263
Q

Sulphur Dioxide disadvantages

A

1) some people are allergic
2) bleaches color of red wine and can result in loss of fruit (although wine does partially recover when free sulphur levels have diminished

264
Q

Sulphur Dioxide Antioxidant

A

readily combines with Oxygen

H2SO3 + [O] –> H2SO4
Sulphurous Acid + O –> Sulphuric Acid

it is however possible for oxygen and sulphur dioxide to coexist before reaction takes place

265
Q

Sulphur Dioxide Anti-Mircrobial

A

Acetobacter is aerobic, so controlled by SO2 which also controls O which Acetobacter needs.

antiseptic property also used to prevent ML by attacking lactobacillus

266
Q

Sulphur Dioxide Anti-Oxidasic

A

SO2 controls oxidases

267
Q

Sulphur Dioxide after oxidation

A

Can freshen wines suffering from a degree of oxidation

one of main products of oxidation is acetaldehyde which SO2 binds with converting it into an odorless and tasteless bisulphite addition compound

268
Q

Free and Total SO2

A

badly made and oxidized wines have a higher proportion of aldehydes and ketones thus greater proportion of SO2 becomes bound

EU regulates total SO2 150mg/l for dry red to 400 g/l for botrytized wines

269
Q

Molecular SO2

A

SO2 + H2O H+ + HSO3-

Only molecular SO2 possesses protective properties. At low pH wines have higher portion of Molecular SO2 and therefore require less of it

270
Q

Ascorbic Acid

A

turns to Hydrogen Peroxide when oxidized. therefore SO2 must be used in conjunction. Used in GER, NZ, AUS because keeps whites ultra fresh. Isomeric form Erythorbic acid used in AUS instead (because it is cheaper) but not allowed in wines sold in EU

271
Q

Sorbic Acid

A

Not a fungicide but does prevent fermentation by interfering with yeast metabolism. Dependent on presence of SO2, alcohol, and acidity. EU limit of 200 mg/l but most bottle at 150 which is fine for 12% wines.

Wine containing sorbic acid must be free of bacteria. Must be added just prior to aseptic bottling because has no bactericidal properties. Can cause smell of geranium leaves when metabolized by bacteria by forming 2-ethoxycarbonyl-3,5-hexadiene.

272
Q

Citric Acid

A

added to wines with excessive amount of iron. Prevents Iron casse by forming soluble complex with iron.

must be added to finished wine because yeast will convert into acetic acid

273
Q

Copper Sulphate or Silver Chloride

A

Hydrogen Sulphide results from reduction of SO2. Copper binds with hyrdrogen sulphite and precipitates as copper sulphide.

Silver Chloride used for the same purpose

274
Q

Acacia

A

Gum Arabic is a stable colloid that will prevent crystallisation of tartrates. Must be added after cold stabilization because it will prevent crystallization during chilling process

275
Q

Pectinolytic enzymes

A

when added to grapes in press decreases viscosity of juice allowing better extraction.

Can also be added to must after pressing. Reduction in viscosity enables a quicker and more effective clarification.

276
Q

Betaclucanase

A

B-Glucan which results from botrytis infection or grapes that suffered attack of grey mold is a large molecule and block all membrane filters. Betaclucanase added after fermentation eliminates B-Glucan.

Another method of overcoming filtration problems is by heating wine to 25C B-Glucan molecules change shape, the viscosity of the wine drops and wine becomes filterable

277
Q

Lysozyme

A

found in protective fluids (tears, saliva, mucus). kills certain types (gram positive) such as Oenococcus oeni, Pediococcus, and Lactobacillus thus preventing or delaying ML. Has no effect on gram negative bacteria such as acetobacter or on yeasts

278
Q

Laccase

A

present in grapes that have been attacked by botrytis. It is a polyphenoloxidase and will turn wine deep gold or even brown. This is a major problem with red wines

279
Q

Tyrosinase

A

a polyphenoloxidase that is present in healthy grapes. It is susceptible to SO2 therefore not too much of a problem.

280
Q

depth filtration

A

kieselguhr (earth filtration) or sheets (pad filtration)

281
Q

rotary vacuum filter

A

filters course liquid. used primarily for the lees. disadvantage is exposure and risk of oxidation

282
Q

earth filter

A

totally enclosed and can be flushed with nitrogen. Machine is expensive but Kieselguhr is cheap and available in a variety of particle sizes allowing everything from simple clarification to yeast removal.

283
Q

Sheet filters (plate and frame or pad filters)

A

used after the gross solid matter has been removed. It is possible to remove microorganisms with the finest grade of sheets. These are known as sterilizing sheets and are frequently used for removing yeast and bacteria prior to bottling

284
Q

Membrane (cartridge filters)

A

can only be used as final filtration of wine that is already very clean. Unlike depth filtration units the equipment is cheap but the filters are expensive.

285
Q

Membrane filter sizes

A
  1. 2u largest size will remove most yeasts
  2. 8u removes all yeast but not all bacteria
  3. 45u removes all yeast and all bacteria

wines that are most susceptible should be filtered at 0.45u. wines that are less susceptible can be filtered less finely

286
Q

crossflow filtration

A

can filter extremely dirty liquid to bottling standard in one pass and can be fitted with appropriate size of membrane. very expensive but only form of filtration needed

287
Q

Ultrafilltration

A

uses extremely small membranes that can actually filter out individual components of wine

WSET Sparkling Wine (19 decks)

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