Viticulture/Wine Making Flashcards
(287 cards)
1
Q
below about what temperature is the vine dormant
A
10C
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
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
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
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
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
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
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
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
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
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
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
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)
14
Q
1mm of rainfall on one square meter
A
1 litre
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
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)
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
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+
19
Q
loam
A
balanced mixture of clay, silt, and sand
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
21
Q
chalk
A
formed like limestone but has a lower density and is more free draining found in Champagne and Jerez
22
Q
dolomite
A
similar to limestone but with high levels of magnesium
23
Q
sandstone
A
made up of compressed sand (quartz)
24
Q
shale
A
sedimentary rock originally composed of clay and is very soft
25
slate
shale that has been metamorphosised. ls harder and less porous than shale
26
granite
extremely hard and dense but still free draining
27
N
major constituent of cell proteins, nucleic acids, chlorophyll, and hormones. 2nd only to water in importance for plant growth
28
P
a key element in energy fixation. encourages root growth and ripening
29
K
regulates the flow of water and sugar in the plant which encourages ripening
30
Ca
regulates cell acidity and is an important component of cell walls
31
S
an essential constituent of some amino acids and enzymes
32
Mg
and essential component of chlorophyll, regulates internal acidity, sugar metabolism, encourages ripening
33
petiole
leaf stalk
34
floral initiation
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
35
budburst
vines sensitive to late spring frosts at this stage
36
coulure
failure of berries to set or fertilize
37
layering
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
38
v. labrusca
found wild in NE USA. dark berries described as "foxy." parent of american hybrids such as Concord.
39
v. riparia
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
40
chlorosis
iron deficiency
41
v. rupestris
found in southern center of USA. vigorous and deep rooting. susceptible to chlorosis. good choice of rootstock for poor soils with limited water availability.
42
v. berlandieri
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
43
True/False. v. riparia is low in vigor
True
44
This rootstock is resistant to chlorosis
v. berlandieri
45
True/False. v. berlandieri has low vigor
False
46
True/False. v. riparia is drought resistant
False
47
True/False. v. rupestris is drought resistant
True
48
True/False. chardonnay is prone to Grey Rot
True
49
True/False. Chenin Blanc ripens unevenly
True. common to find leafy and tropical aromas in the same wine
50
True/False. Cabernet Sauvignon gives high yields despite low vigor.
True
51
Tempranillo can ripen with high levels of malic acid.
True. Therefore by-products of MLF are distinctive.
52
Pratylenchus and Meloidogyne
species of Nematode that cause damage by feeding off roots
53
Xiphinema Index
species of Nematode that spreads viral disease
54
true/false. v. riparia based rootstocks are drought resistant.
false. they are however able to tolerate damp conditions
55
v. rupestris will have _____ vigor
High
56
v. riparia will have _____ vigor
Low
57
True/False. Low vigor rootstocks are usually used in cooler climates.
True. They encourage earlier wine production and in quality wine production they can help control yield.
58
Riparia Gloire de Montpellier
```
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.
```
59
Rupestris du Lot
```
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
```
60
AXR1
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
61
3309 C (Couderc)
```
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.
```
62
101-14 (Millardet et de Grasset)
```
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
```
63
Schwarzman
```
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
```
64
riparia x rupestris
halfway between surface and deep rooting. average vigor. Good resistance to phylloxera but poor resistance to chlorosis
65
riparia x berlandieri
surface to semi-surface. Good rooting, high resistance to chlorosis. Good affinity with scions and resistance to phylloxera.
66
161 - 49C (Couderc)
```
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.
```
67
420A (Millardet et de Grasset)
```
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
```
68
5C (Teleki)
```
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.
```
69
5BB (Teleki Selection Kober)
```
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
```
70
SO4 Selection Oppenheim
```
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.
```
71
125AA (Kober)
```
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
```
72
berlandieri x rupestris
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.
73
99R (Richter)
```
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
```
74
110R (Richter)
```
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
```
75
140 RU (Ruggieri)
```
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
```
76
1103 P (Paulsen)
```
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
```
77
This rootstock is saline resistant
1103 P. berlandieri x rupestris
78
Berlandieri x vinifera
good resistance to lime and chlorosis.
| some have poor resistance to phylloxera
79
Fercal
```
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
```
80
41B (Millardet et de Grasset)
```
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.
```
81
This rootstock has good uptake of Mg
41B
82
333EM (Ecole de Montpellier)
```
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.
```
83
Vitis Champini
Important for regions with severe nematode problems, but tends to be extremely vigorous, and unsuitable for high quality grapes
84
Dog Ridge
```
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
```
85
High density planting often increases or decreases the total effective leaf area
increases
86
balance between vine's root system and its canopy is determined by:
vigor of the vine, planting density, fertility of the soil, and the training system
87
main drawback of single wire trellis system
shoots often hang down offering no protection to the fruit from sunburn
88
VSP
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
89
cane-pruning and spur-pruning poduce
uniformly trained shoots where all the fruit is in one zone and the shoot tips are in another.
90
main disadvantage of VSP
shoot density is normally high therefore prone to shade. unsuited to high vigor varieties and to high potential sites
91
divided canopies (either vertically or horizontally) provide
less shape
92
Scott-Henry
Vertical, divided trellis system.
| Head trained, Cane-pruned
93
Smart-Dyson
Vertical, divided trellis system
Cordon trained, Spur-pruned
upward and downward pointing spurs create two canopies
can be machine pruned
94
head training
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.
95
cordon training
trunk terminates in a cordon and is normally subject to spur pruning
96
cane pruning
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
97
spur pruning
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
98
GDC
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
99
U-shaped or Lyre
horizontally divided trellis with shoots trained upward in two curtains. very high cost of construction and maintenance
100
Prior to planting soil pH should be increased to over ____
6.5%
101
3 soils additions that raise soil pH
Calcite (Calcium Carbonate), Magnesite (Magnesium Carbonate), or Dolomite (a combination of both)
102
Guyot
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.
103
main advantage and disadvantage of replacement cane pruning
advantage: by limiting the carbohydrate reserves the vine's vigor is kept under control
disadvantage: requires great skill cannot be mechanized
104
main advantage and disadvantage of of cordon/spur pruning
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
105
bud-rubbing
removal of a potentially undesirable shoot before it has a chance to grow
106
leaf stripping
done between veraison and harvest to improve canopy microclimate, allow spray penetration, speed manual harvesting. Can take up to 70hrs/hectare
107
Green Harvesting
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.
108
chlorosis
yellowing of foliage caused by deficiency of iron, nitrogen, magnesium, and/or sulfur
109
Cultivation vs. "no-till cultivation"
No-till cultivation is done chemically
110
sucrose
sugar generated in leaves converted to glucose and fructose in grapes
111
enzyme
catalyst for reaction
112
resveratrol
a phytoalexin, protects plant from fungal disease
113
planting density
way of controlling division of soil resources amongst right number of plants
114
partial root drying
used to trick vine into allocating resources to fruit ripening rather than vegetative growth
115
viticulture raisonee (La Lutte Raisonee)
'the reasoned fight' supported by the Terra Vitis Organization
116
photosynthesis
12CO2 + 11H2O --> C12H22O11 + 12O2
117
hydrolysis of scurose
C12H22O11 + H20 --> C6H12O6 + C6H12O6
| Sucrose + Water --> Glucose + Fructose
118
Sweetness of sugars
Fructose, Sucrose, Glucose is the least sweet. Plants prefer Glucose leaving Fructose as the principal sweetener in sweet wines
119
Malic Acid
L. Malus = apple.
As the grape matures Malic Acid level diminishes. Because grape consumes malic acid as an energy source, then guconeogenesis
120
Tartaric Acid
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
phenolic compounds
Non-flavanoids, and flavanoids (polyphenols)
| polyphenols can be sub-divided into tannins and anthocyanins
122
non-flavanoids
smaller molecules based on benzoic acid and cinnamic acid. influence on flavor relatively minor
123
Hydrogen Sulfide
H2S
124
oxidation of alcohol
CH3CH2OH + O2 --> CH3COOH + H2O
| Ethanol + Oxygen --> Acetic Acid + Water
125
Reductive Taint
Sulphur Dioxide becomes chemically reduced to Hydrogen Sulphide
126
Potassium Metabisulphite
white powder stable when dry liberates SO2 when wet
used in the vineyard to protect grapes en route to winery
127
CO2
cheap and effective antioxidant
but soluble in wine (more soluble at lower temp)
around 800mg/l in whites and pinks important constituent
128
Argon
expensive but effective alternative to CO2 and N
129
Dissolved O
every molecule of oxygen destroys 4 times its weight of SO2
2SO2 + O2 --> 2SO3
128 32
130
Sparging
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
Must
product of crushing is known as must from Latin Mustum meaning fresh or new.
White wine - Juice
Red wine - Juice + Skins
132
Crushing
ripping open grape to allow free-run juice to flow out
optional: crush or leave intact for direct pressing
133
Pressing
extraction of juice remaining after crushings
principle of pressing: use minimum pressure required to achieve necessary extraction
134
pectinolytic enzymes
releases more juice from the pulp by breaking down gelatinous pectins
135
Draining
draining process is slower than other stages and can pose a problem of through-put
136
free-run juice
for whites free-run juice is typically between 400 and 500 litres per tonne
137
Pressing the berries
pressing comes after juice released from crushing to release remainder of juice (150 to 200 litres per tonne of grapes)
138
basket press
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
Horizontal Screw Press
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
Pneumatic Press
more efficient pressing at lower pressure
common fault is exposure
141
Tank Press
enclosed Pneumatic Press
142
Continuous Screw Press
efficient, but produces rough juice
143
Whites: Clarification
whites: unfermented must is very susceptible to oxidation almost always protected but SO2 (also to protect from premature fermentation)
exception: hyperoxidation
144
Reds: Clarification
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
Calrification
solid particles are nutritious to yeasts because they have become adsorbed to the surface of amino acids, minerals, and vitamins
146
Ways to clarify
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
Hyperoxidation
counterintuitive: kills more susceptible components of the juice, finished wine is more stable
148
Acidification
usually tartaric, citric is cheaper but can be metabolized by some yeasts and converted to acetic,
149
plastering
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
Deacidification
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
double salt deacification
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
vacuum distillation
concentrating must by boiling must at very low pressure
153
gaseous nitrogen
N2
154
Combined nitrogen
in the form of ammonium NH4. N is necessary for the formation of amino acids/proteins within the yeast cell
155
insufficient nitrogen
fermentation is reductive, in the absence of nitrogen production of hydrogen sulfide. adding diammonium phosphate or ammonium phosphate up to 1g/litre
156
Thiamine
important for growth of yeast populations. allowed to add up to 0.6g/litre
157
Bentonite
sometimes added at must state to remove proteins in order to reduce viscosity. another advantage is will remove polyphenoloxidase
158
activated charcoal
if white wine must is deeply colored treated with up to 100g/l
159
saccharomyces
means sugar-loving
cerevisiae is the most common. It is tolerant of both alcohol and SO2. bayanus associated with sherry production
160
alcoholic fermentation
in the absence of oxygen
yeasts + sugars --> alcohol + CO2 +heat
C6H12O6 --> 2C2H5OH + 2CO2
Glucose Ethanol Carbon Dioxide
180 92 88
161
ethanol weight
0.7897 g/ml
| 17g sugar/l produces 1% alcohol by volume
162
temperature
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
ways to stop fermentation
1) naturally
2) increase CO2 pressure
3) reduce temperature
4) kill yeasts
5) remove yeasts
6) fortification (results in stable wine)
164
naturally sweet wines
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
ML
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
pigeage
punching down cap or chapeau
see also pumping-over method
167
submerged cap process
screen method, prevents efficient extraction
168
delestage
(rack and return). similar to pumping-over
169
rotary fermenters
very effective achieves thorough mixing of skins and juice. However serve disturbance can lead to overextraction
170
thermovinification
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
Flash Detente
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
Carbonic Maceration
intracellular followed by extracellular fermentation
anaerobiosis
press juice is of better quality than free run
173
Whole bunch fermentation
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
pink wine methods
1) short maceration
2) saignee
3) Vin d'une nuit
4) double pasta
175
maceration pelliculaire
skin contact particularly useful for aromatic whites
176
batonnage
stirring introduces oxygen to the lees which prevents reduction, also increases contact with lees increases leesy flavors
177
Pompe Bicyclette
carbonation
178
Fortified Wines
according to EU legislation now called "Liqueur Wines"
179
oxidative coupling
tannins and anthocyanins interact creating stable coloring matter
180
Quercus Alba
American Oak (Penn, Minn, Wisc)
181
Quercus Robur
English Oak or Pedunculate Oak.
Limousin is only forest.
Has a coarser grain and a lower aromatic content particularly useful for agin Cognac
182
Quercus Sessilis
Found in most French Forests i.e. Troncais, Nevers, Allier, and Vosges.
has a tight grain and is rich in aromatic content
183
Slavonian Oak
Quercus Robur
184
IPM
focused on timely preventative measures rather than more costly curative ones
185
Botrytis cinerea
Grey mold, grey rot, ...
| heavily infected white grapes will require more SO2, red grapes will require charcoal fining to remove mouldy taint
186
sclerotia
botrytis overwinters as sclerotia (hard, dark-brown encrustations of the dormant fungus)
187
bunch rot
when botrytis infects flowers can get trapped in center of bunch as grapes expand
188
pre-emergence herbicides
become trapped in soil absorbed through roots
189
systematic herbicides
absorbed by the leaves
190
contact herbicides
'wilters' are only temporary for plants with established root systems
191
obsolete botrytis treatments
Benzimidazole in the 60s and 70s, then dicarboximides both of which were contact fungicides. Botrytis can become resistant to certain chemicals
192
Scala
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
Sentinel
bio-fungicide developed in NZ for preventing botrytis using new strain of predator fungus called Trichoderma harzianum. as effective as other products.
194
Stem rot
bortytis infects stems reults in large numbers of bunches to fall to the ground
195
methods to control botrytis
1) spraying chemicals
| 2) open leaf canopy to allow air movement
196
Noble Rot
Once grapes reach about 7% potential alc. botrytis affects them differently. grapes must be clean prior
197
Downy Mildew
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
Bordeaux Mixture
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
Oidium or Powdery Mildew
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
alternatives to sulphur for treatment of Powdery Mildew
light mineral oil which is also effective on botrytis, and Strobilurins which are sprays developed from a toad stool called Strobilurus Tenacellus.
201
Anthracnose
fungal disease but easily controlled with copper-based sprays
202
Armillaria Root Rot
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
Bacterial Blight
only method of control is to remove infect vines and disinfect secateurs before pruning each vine. Copper sprays help
204
Black Rot
impossible to eradicate but controlled with copper sprays
205
Crown Gall - Black Knot
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
Buttage
ploughing close to vine so earth is piled up around and over the graft prior to winter.
207
Esca
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
Eutypa
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
Grapevine Yellows - Flavescence Doree
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
Phomopsis - Dead Arm
controlled by copper sprays
211
Pierce's disease
caused by bacterium Xylella fastidiosa spread by various insects
212
Corky Bark
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
Fanleaf Degeneration
Viral. Leaves distort and grow in shape of a fan. Then leaves become yellow with yellow veins. Nematodes are vectors
214
Leafroll
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
Nepoviruses
group of 13 viruses spread by nematodes
216
heat treatment of cutting
50C for 30 minutes
217
Phosphorous
on soils with very low pHs, low P levels may lead to chlorosis-like symptoms
218
Potassium Deficiency
Vines deficient in K will show chlorotic leaf margins, often accompanied by cupping of the leaves.
219
Soil Potassium
Excess K in soil often associated with high pH in wine. Soils high in K tend to be deficient in Mg
220
Iron
Iron is required for chlorophyll production. deficiencies associated with high pH soils
221
Chlorosis
high pH soils (7.5 +) fix iron which is required for photosynthesis
222
Coulure
poor flowering conditions and/or an imbalance of nutrients
223
Millerandage
condition resulting in un-pollinated flowers or very small berries sans seeds
224
Barrique
Bordeux. 225 litres
225
Gonci
Hungary. 130 litres
226
Micro-Oxygenation
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
Ethyl Acetate
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
VA
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
RS
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
glycerol
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
Acetaldehyde
precursor of ethanol during fermentation also product of its oxidationt
232
yeast bitten
wine that has been left in contac for too long with the gross lees is said to be yeast bitten
233
Finingg
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
Colloids
Stabe vs Unstable
| Acacia (gum arabic) is a stable colloid used to increase wine stability
235
Ox Blood
prohibited in EU since 1987. Active ingredient is Albumin
236
Albumin
effective at removing harsh tannins and troublesome colloids
237
Gelatin
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
Silica Sol
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
Casein
useful for decolorizing white wines
240
Tannin for fining
wood tannins used in conjunction with gelatin precipitate first with the gelatin then bring down colloidal proteins
241
Bentonite
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
Egg Whites
used in production of fine reds by adsorbing harsh tannins and excess colloids
243
Oenological Tannins
will inhibit Laccase activity from botrytis on red grapes
244
Isiglass
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
PVPP
used to remove phenolic compounds from whites especially those that are suffering from pinking or browning
246
Charcoal
used to remove brown colors and off odors
247
Blue Fining
removal of excess iron and copper. Particularly useful for removing copper as this is the
248
Calcium Phytate
removes excess iron from red wines by precipitating out as soluble ferric phytate
249
PVI/PVP copolymers
plastic meterial absorbs metal ions such as iron and copper
250
Chitin-glucan
polysaccharide and fungal resource used as a fining agent. produced from aspergillus niger
251
Chitosan
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
Super-Saturation
tartrate concentration exceeds solubility limit after fermentation because they are less soluble due to the presence of alcohol
253
tartrate crystals
form after colloids denature.
254
Cold stabalization
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
Contact Process
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
Ion Exchange
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
Electrodialysis
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
metatartaric acid
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
Carboxymethylcellulose
similar to metatartaric acid but lasts longer. EU limit is 100 mg/l
260
Mannoproteins
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
Sulphurous Acid
SO2 + H2O --> H2SO3
262
Potassium Metabisulphite
K2S2O5
releases 57% of its weight when dissolved in acid aqueous solution
263
Sulphur Dioxide disadvantages
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
Sulphur Dioxide Antioxidant
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
Sulphur Dioxide Anti-Mircrobial
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
Sulphur Dioxide Anti-Oxidasic
SO2 controls oxidases
267
Sulphur Dioxide after oxidation
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
Free and Total SO2
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
Molecular SO2
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
Ascorbic Acid
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
Sorbic Acid
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
Citric Acid
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
Copper Sulphate or Silver Chloride
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
Acacia
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
Pectinolytic enzymes
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
Betaclucanase
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
Lysozyme
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
Laccase
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
Tyrosinase
a polyphenoloxidase that is present in healthy grapes. It is susceptible to SO2 therefore not too much of a problem.
280
depth filtration
kieselguhr (earth filtration) or sheets (pad filtration)
281
rotary vacuum filter
filters course liquid. used primarily for the lees. disadvantage is exposure and risk of oxidation
282
earth filter
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
Sheet filters (plate and frame or pad filters)
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
Membrane (cartridge filters)
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
Membrane filter sizes
1. 2u largest size will remove most yeasts
0. 8u removes all yeast but not all bacteria
0. 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
crossflow filtration
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
Ultrafilltration
uses extremely small membranes that can actually filter out individual components of wine
