WSET4 D1 definitions Flashcards
1
Q
Vine density
A
number of vines that are planted per hectare of vineyard, ranging from few 100 to >10.000 per hectare. Influenced by vine vigour, trellising system and acces needed between the vines.
2
Q
Aroma precursors
A
compounds that have no flavour in the must, but are released by the action of yeast and create aromas in the wine (e.g. thiols (=4MMP in SB) + terpenes (=linalool and gerianiol in Muscat))
3
Q
Bloom
A
powdery waxy coating on surface of grape
4
Q
Bunch
A
fertilised inflorescence, differencing in size, shape and tightness depending on grape varieties and clones (e.g. Pinot Noir being very tight, increasing the risk of grape-skin splitting during growth and lack of airflow = prone to funghal diseases).
5
Q
Canes
A
lignifying green shoots (becoming woody and brown)
6
Q
Canopy
A
concerning shoot and major structures (bud, leaves, lateral shoots, tendrils and inflorescences)
7
Q
Chlorosis
A
Condition in which leaves turn yellow and photosynthesis stops, resulting into low yields and poor grape ripening, caused by low levels of iron common to soils with high pH. (e.g. soils with high proportion of calcium carbonate such as limestone)
8
Q
Clonal selection
A
process by which particular vines are selected by vine nurseries for propagation by cuttings in order to grow new vines with the desired characteristics (e.g. Pinot Noir clones 115 (high quality red) and 521 (sparkling wines (higher yield and bigger grapes))
9
Q
Compound buds
A
(=Latent buds), containing a primary, secondary and tertiary bud, form in one growing season and break open in next growing season, producing shoots with the essential green parts and inflorescences.
10
Q
Cross fertilisation
A
process by which the pollen from one variety are transported on the stigmas of another variety, both from the same grape species, The seeds of the new vine are used to create new grape varieties (off spring) (e.g. Pinotage = Pinot Noir x Cinsault, CS = CF x SB, MT= Riesling x Madeleine Royale)
11
Q
Cutting
A
section(s) taken from a vine to be planted, which is a common way of propagation, permitting the planting of several cuttings at the same time.
12
Q
Hybrid
A
Offspring from two different grape species, bred in attempt to combine the resistance (pest, disease, climatic extremes) of non-vinifera species and the quality of vinifera (e.g. Vidal from Ugni Blanc x Seibel-member (American))
13
Q
Inflorescence
A
cluster of flowers becoming a bunch of grapes when fertilised
14
Q
Internodes
A
Lengths between the nodes
15
Q
Lateral shoots
A
grow on primary shoots, 1.allowing the plant to carry on growing when the tip of the primary shoot has been damaged, 2.can provide an additional source of leaves for photosynthesis and 3.produce second crops.
16
Q
Layering
A
Propagation technique by which a shoot, still attached to an established vine, is being buried, takes root and grows on its own when cut loose from the original vine.
17
Q
Leaves
A
main site of photosynthesis, containing stomata (pores)
18
Q
Mass selection
A
(sélection massale) a propagation process by which vineyard owners take cuttings from vines in their own vineyard and cultivate the cuttings themselves, increasing diversity of planting material, but also increasing the spread of vine diseases.
19
Q
Nodes
A
Swellings along the shoot
20
Q
One-year-old wood
A
left shoots from the previous growing season turned into a cane or spur
21
Q
Permanent wood
A
woody parts older than one year including the trunk and possible cordons, 1. providing support, 2. transporting water and solutes and 3. storing carbohydrates and nutrients.
22
Q
Petiole
A
Leef stalk
23
Q
Prompt buds
A
form and break open in same season, producing lateral shoots
24
Q
Pulp
A
inside of the grape excluding seeds, containing water, sugar, acids, and aroma compounds and precursors. Mostly colourless.
25
Second crop
inflorescences produced by lateral shoots, depending on grape variety (e.g. Pinot Noir) and can be removed during canopy management (green harvest)
26
Seeds
maturing inside the grape, containing oils, tannins and the embryo
27
Skin
outer surface of the grape containing high concentration of aroma compounds and precursors, tannins and colour compounds
28
Solutes
substances dissolved in a liquid, including sugars and minerals, providing nutrients for vine parts.
29
Stomata
pores on the underside of the leaves, essential for the transpiration process, letting water diffuse out (transpiration) and CO2 to enter
30
Tendrils
enabling the plant to attach itself to other trees and plants or a trellis
31
Tenturier
grapes with red-coloured pulp instead of colourless (e.g. Alicante Bouschet)
32
Bud fruitfulness
number of inflorescences developing from a latent bud, depending on conditions during Flowering and Fruitset of previous growing season (1.light-exposure 2.min. 25 C 3.NO water stress 4.sufficient nutrients and 5.grape variety (e.g. Riesling has high bud fruitfulness at low temp.)
33
Budburst
(budbreak) Process starting at average temperatures above 10 C, in which buds swell and open and green shoots start to emerge, depending on 1.air temperature 2.soil temperature 3.grape variety 4.human factors (pruning).
34
Coulure
Condition of the grape bunch in which fruit set has failed for a high proportion of flowers, occuring when ovule fertilisation is unsuccessful and caused by an imbalance of carbohydrate levels (water stress or vigorous shoot growth). Also depending on variety (e.g. Genache, CS, Merlot, Malbec are susceptible)
35
Early Budding
Grape varieties that require relatively low temperatures at budburst e.g. Chardonnay, Pinot Noir, Merlot and Grenache.
36
Early Grape Growth
starting after fruit set in which grapes grow in size, acids and tannins accumulate, aroma compounds and precursurs develop and shoot growth continues.
37
Early Ripening
Describing grape varieties that naturally ripen earlier than others (e.g. Chardonnay and Pinot Noir).
38
Extra-Ripening
Last (optional) stage of grape development in which grapes start to shrivel; no more sugar and water are imported by the phloem and sugars are concentrated due to water loss. Also depending on 1.grape variety (e.g. Syrah is susceptible) 2. weather conditions and 3.disease pressure 4.style of wine
39
Fertilisation
Process of sperm cells transported to the ovule by the pollen tube, fertilizing the eggs in the ovule, leading to fruit set
40
Flowering
process (occuring within 8 weeks of budburst) in which pollen-laden stamens (filament + anther) are exposed by the opening of the flowers within an inflorescence for the pollination process
41
Fruit set
process of transition from flower to grape, in which the fertilised ovules form the seeds and the enlarging wall of the ovary form the skin and pulp
42
Grape Development
Stage of growth cycle starting after fruit set and split into 4 stages, to know Early Grape Growth, Véraison, Ripening and Extra-Ripening.
43
Lag phase
stage in which grape growth slows down, part of the véraison stage
44
Late budding
Grape varieties that require higher temperatures at budburst, e.g. Sauvignon Blanc, Ugni Blanc, Cabernet Sauvignon and Syrah
45
Late Ripening
Describing grape varieties that naturally ripen later than others (e.g. CS and Grenache).
46
Methoxypyrazines
aromatic compounds that contribute to herbaceous aromas and flavours, decreasing during ripening stage depending on temperatures and sunlight
47
Millerandage
Condition occuring in case of cold, wet and windy weather at fruit set, in which there is a high proportion of seedless grapes, resulting in smaller (+green+unripe) grapes of less volume and/or quality. Also depending on variety. (e.g. Chardonnay and Merlot are susceptible)
48
Ovule
The female reproductive cells containing eggs
49
Phloem
type of transport tissue that transfers sugar solution from the leaves to the rest of the vine during stage of ripening. The rapidity of this transport is correlated to the rate of grape transpiration, depending on weather conditions.
50
Photosynthesis
process by which green plants use sunlight to produce sugars from CO2 and water, used for vine growth and metabolism, optimally occuring at a temperature range of 18-33 C
51
Pollen tube
Delivers the sperm cells that fertilize the eggs in the ovule
52
Pollination
process in which pollen grains are shed and land on the stigma surface of the flower, where they germinate, with each pollen grain producing a pollen tube, that will penetrate the stigma and the ovule for fertilisation.
53
Polymerisation
process during ripening in which relatively small molecules combine chemically to produce a large network molecule (tannins getting less bitter)
54
Respiration
Process in which energy is released from food substances for vine growth (e.g. malic acid metabolised during ripening).
55
Ripening
Stage during grape development in which 1.grape cells expand rapidly, 2.sugar and water accumulate, 3.tartaric acids dillute 4.malic acids partly metabolize 5.aroma compounds and precursors increase (exc. Methoxypyrazines!) 6.tannins polymerize and 7.anthocyanins increase.
56
Self-pollinating
Pollens are transferred to the stigma of the same flower or different flower in the same plant.
57
Transpiration
Process in which water vapour diffuses out of the stomata, causing water to be pulled upwards from the soil, through the roots and the above-ground parts of the vine. This process also provides the exchange of Co2 and O2 in and out of the leaves, important for photosynthesis.
58
Véraison
Stage during grape development in which grape growth slows down (lag phase), cell wands become stretchy, chlorophyll in skins cells is broken down and anthocyanins synthesise.
59
vigour
describing vegetative vine growth, including the growth of the shoots, leaves and lateral shoots, depending on 1.natural resources 2.planting material 3.presence of disease, and has implications on the yield and ripening.
60
Water stress
Occuring in case of low water availability during Flowering & Fruit Set and Grape Development, causing the vine to close its stomata partially to conserve water, but also reduces or stop photosynthesis due to lack of carbondioxide entering the leaves, resulting in stunted vine growth and slower ripening.
61
Winter dormancy
Stage of growth cycle starting at temperatures below 10 C with leaf fall in autum (thus unable to photosynthesise), ending with budburst in the spring and sustaining itself by using carbohydrates (starch) stored in the roots, trunk and branches. Temperatures below -20 C should be avoided (e.g. Canada, New York State and China)
62
Xylem
type of transport tissue during early grape growth that transfers water and some nutrients from the roots to the rest of the vine
63
Calcium
Nutrient important for the structure of plant cells and photosynthesis, also causing a lower fruit set in case of deficiency.
64
Climate
annual pattern of temperature, sunlight, rainfall, humidity and wind averaged out over several years (30 years)
65
Continentality
measure of the difference between the annual mean temperatures of the hottest and coldest months, influenced by both landmasses (high) and large bodies of water (low).
66
Diurnal range
describing the average difference between day-time and night-time temperatures, effecting the development of the grapes, also depending on the grape variety, time in the growing season and availability of water.
67
El Niño
Phase of the ENSO, starting when warm water in the western Pacific Ocean moves eastwards along the Equator towards the Caribbean, resulting in the eastern Pacific Ocean becoming warmer than average, tending to cause high levels of rainfall and risk of hurricanes in South America and California.
68
ENSO
(El Niño Southern Oscillation (=climate pattern)) defining a climatic cycle in the Pacific Ocean, concerning two opposite phases (El Niño/La Niña)
69
Evapotranspiration Rate
Amount of transpiration from the vine, combined with the evaporation of water from the soil surface, depending on temperature, humidity. (e.g. Mendoza and Patagonia = high due hot, dry and windy weather)
70
Frost pocket
Area with risks of frost damage due to accumulated cold air by lack of sufficiënt air drainage.
71
La Niña
Phase of the ENSO, caused when the eastern Pacific Ocean is cooler than average, tending to result in cooler, wetter conditions in Washington, Oregon and Australia, but warmer, drier conditions in California and South America.
72
Magnesium
Nutrient found in chlorophyll, and key in photosynthesis, causing low yields and poor ripening in case of deficiency
73
Micro-oxygenation
Bubbling oxygen through wine after fermentation to 1.increase colour stability and intensity, 2.soften tannins, 3.improve texture and 4.reduce presence of unripe, herbaceous flavours 5.help to integrate oak-influences when used. typically in units of mg/L per month and generally carried out in stainless steel tanks for a number of months. Technique gaining popularity because of level of control and efficiency. Effects on long term are questionable.
74
Mineralisation
process in which organisms convert organic nutrient compounds into inorganic ones, that do not contain carbon anymore
75
Mists
Formed by tiny drops of water collecting in the air just above an area of ground or water and when warm air is rapidly cooled, causing water vapour in the air to condense (e.g. warm air over water meeting cooler conditions above land at night).
76
Nitrogen
Nutrient being a component of proteins and chlorophyll required for photosynthesis and therefore essential for vine growth and also impacting vine vigour and grape quality depending on the amount of it.
77
Phosphorus
Nutrient important for photosynthesis and, in case of deficiency, negatively influencing the development of root systems (thus the uptake of water and nutrients) and thereby vine growth and yield.
78
Potassium
Nutrient helping to regulate the flow of water in the vine and essential for vine growth, also correllated to PH range and causing low sugar accumulation in case of low levels, leading to reduced yields and poor vine growth and causing problems in the uptake of magnesium in case of high levels.
79
Rainfall
caused by moisture from the land evaporated by warm temperatures, that will rise in the atmosphere where it cools and condenses into clouds and eventually precipitate.
80
Soil
upper layer of the earth made up of geological sediment, organic remains (humus) and the pores in the sediment containing water and air, defining the texture and structure influencing the suitability for vineyard establishment.
81
Vintage variation
term used to explain the style and quality differences of wine significantly influenced by yearly weather circumstances.
82
Weather
Annual variation that happens relative to the climatic average, influencing vintage variation and affecting yield.
83
Agro-ecosystems
functioning ecosystem explained in the regenerative viticulture created by the grape grower in which the system's needs are met naturally, resulting in reduce of fertilizers and more resistance to climate change-related threats like drought and heat
84
Ashing
Method used in biodynamic viticulture in which ashes of burnt weed seeds or harmful animals are spread to ward them off.
85
Biodynamic Viticulture
method of farming based on the work of Rudolf Steiner and Maria Thun, including organic practices, but also incorporates philosophy and cosmology, and seeking to achieve balance between the physical and higher, non-physical realms. (e.g. calendars based on root, leaf, flower or fruit days and use of preparations)
86
Conventional Viticulture
Intensive fruitfarming (monoculture), mainly aiming on raising production levels and reducing labour requirements, achieved by mechanisation, chemical inputs, irrigation and clonal selection.
87
Demeter
Institute which sets the international standards for biodynamic farming and animal husbandry, including organic certification and specifying required principles to follow.
88
Dynamizing
Process performed with making Preparation 500 + 501, describing the action of stirring contents of a horn so that the water is said to memorise the power of the preparation, which can then be passed on to the vineyard.
89
GIS
(Geographical information systems) A type of geospatial technology used in precision viticulture for visually presenting 'remote' or 'proximal' data from the vineyard
90
GPS
(Global positioning systems), used in precision viticulture for visually presenting 'remote' or 'proximal' data from the vineyard
91
Green manure
cover crop or natural vegetation that, when ploughed in the soil, can provide organic matter for fertilising the soil
92
IFOAM
International Federation of Organic Agriculture Movements, institute that sets the standards of certification for organic viticulture, requiring the vineyard undergoing a period of conversion working to organic standards before it can be certified
93
IPM
Integrated Pest Management (lutte raisonnée) is a method of sustainable viticulture where chemical interventions are only used when necessary, for instance setting thresholds for actions, identifying and monitoring pests, setting up preventative measures and evaluating and implementing control options
94
Mycorrhizal funghi
Example of an organism that forms symbiotic relationships (encouraged in regenerative viticulture) with plants and vines allowing them to better absorb nutrients like phosporos, nitrogen and water.
95
Organic Viticulture
method of farming seeking to improve the soil of the vineyard and the range of microbes and animals and thereby increase the health and disease-resistance of the vine
96
Precision viticulture
method of farming using data collected from the vineyard, presented by GPS or GIS, to respond to changes from plot to plot and from row to row.
97
Preparation 500
(horn manure) made by stuffing cow manure into a cow's horn, buried in the soil throughout the winter. After dynamizing it is sprayed onto the soil, believed to catalyse humus formation
98
Preparation 501
(horn manure) made by filling a cow's horn with ground quartz, buried in the soil for 6 months. After dynamizing it is sprayed onto the soil, believed to encourage plant growth.
99
Preparations
Homeopathic remedies used in the biodynamic viticulture to fertilise soil, treat diseases and enhance and strengthen the life forces on the farm
100
Preparations 502-508
series of starters added to activate compost (e.g. yarrow, chamomile, nettle, oak bark, dandelion or valerian prepared in various ways)
101
Regenerative Viticulture
holistic method of farming that aims to continually improve (instead of maintaining) environmental, social and economic measures. Important tenets are soil health and developing vineyards as agroecosystems.
102
ROA
Regenerative Organic Alliance, agency that measures the key features of regenerative viticulture, including soil health, animal welfare and human empowerment, when certifying a producer.
103
Sexual Confusion
Technique involving pheromone tags and capsules used in organic viticulture to disrupt the mating patterns of insects (e.g. moths, mealy bugs) resulting in limited populations
104
Soil Health
A core tenet of regenerative viticulture, describing the continued capacity of the soil to act as a living ecosystem that sustains plants, animals and humans.
105
Sustainable Viticulture
grape growing method concerning economic, social and environmental sustainability, primarily focusing on environmental impact
106
Variable-rate application technology
Method used in precision viticulture by which interventions in a vineyard are targeted in the light of the collected data.
107
Aspect
Defines the particular direction a slope is faced to, influencing the amount of solar radiation and thereby the intensity of heat and light.
108
Geological sediment
coming from weathering of bedrock below the soil, containing solid matter in the form of sand, pebbles and rocks
109
Head grafting
(Top grafting), method of grafting a bud from a new grape variety on the trunk of an existing vine, benefitting from an establisched root system and therefore producing fruit more quickly. Disadvantage can be that the characteristics of the new variety is not equally suited to the rootstock.
110
Mutation
change occuring in genetic code of variety that, depending on the significancy, can be classified as a new grape variety (e.g. Pinot Noir, Meunier, Pinot Blanc, Pinot Gris from Pinot)
111
Subsoiling
process of breaking down the plough plan (impervious layer of soil) formed by previous plouging for agriculture, promoting better drainage and easier cultivation of the soil
112
Channel irrigation
similar to flood irrigation, but water flows down furrows dug between the vine rows.
113
contact herbicides
chemicals sprayed on established weeds, killing the green parts of the weed that they contact
114
Cover Crops
plants that are specifically planted, or allowed to grow that have a beneficial effect on the vineyard. Examples include legumes (beans and clover) and various cereals (ryegrass and oats). Use of natural vegetation can have the same function.
115
Cultivation
Method of weed control that involves ploughing the soil to cut or disturb root systems
116
Drip irrigation
system consisting of water pipes laid along each row attached to the lowest trellis wire, with drippers positioned far enough away from the vines to encourage roots to grow and seek out water. Not suitable for water high in dissolved solids or high salinity. (salt accumulates around roots, resulting in dehydrating the vine)
117
Dry farming
referring to not using irrigation in areas with limited rainfall in growing season to potentially improve grape quality.
118
Fertigation
Method by which liquid fertiliser is added to water supply such as drip irrigation
119
Flood irrigation
irrigation system by which water is stored behind a sluice and at scheduled time released to flood the vineyard
120
Inorganic Fertilisers
(synthetic fertilisers) fertilisers manufactured from soil minerals or synthetic chemicals
121
Mulching
Practice done in organic and biodynamic viticulture, by which organic matter (e.g. straw or bark chips) are spread onto the vineyard soil to suppress growth of weed, but also reduces water evaporation and can be a source of nutrients and humus.
122
Organic Fertilisers
fertilisers derived from fresh or composted plant or animal material (e.g. manure, slurry or green manure (mowned and turned cover crops))
123
Overhead sprinklers
system in which water is pumped and showered over the vineyard, also suitable for aspersion
124
Pre-emergence herbicides
chemicals sprayed before weeds establish, persisting in the surface layers of the soil, but absorbed by weeds' roots and inhibiting germination of young seedlings
125
RDI
(Regulated Deficit Irrigation) system of timing and regulating the amount of irrigation so that the vine is put under mild or moderated water stress, usually scheduled between fruit set and véraison
126
systemic herbicides
chemicals sprayed on established weeds, taken in by the leaves and transported inside the whole weed by its sap and killing the whole plant
127
green harvesting
canopy management technique performed during grape development by which (second) crops can be removed to enhance the ripening process and improve the uniformity of ripeness of remaining bunches
128
Head training
Vines with little permanent wood, either being spur pruned (mechanisation possible) or replacement cane pruned (skilled labour required)
129
Vigour
Term used to describe vegetative vine growth
130
Vine training
referring to the shape of the permanent wood of the vine, split into head training or cordon training and can be trained high (avoiding frosts + easier manual interventions) or low (heat retained from soil + wind protection)
131
Aspersion
Water sprinkler system used for frost protection
132
Bacillus subtilis
bacterium competing with botrytis cinerea (grey rot), a natural predator used in organic viticulture
133
Nematodes
Microscopic worms (e.g. root-knot and dagger) causing damage by 1.feeding off vine roots, 2.reducing yields and vigour and 3.transmitting viral diseases (dagger = fanleaf). Spread by unclean nursery stock, irrigation water or vehicles.
Elimination is not possible. Other options:
fumigation by using mustard plant (biofumigant), or planting on Champini Rootstocks (Ramsey or Dog ridge).
134
Sunburn
condition of a grape that has too much sun-exposure, resulting into 1.scars that create bitter taste and susceptibility to rot 2.heated grapes because of less effective grape transpiration
135
Acetaldehyde
(ethanal) oxidation of ethanol, creating nutty or stewed apple aromas. Often experienced as unwanted aromas
136
Rotundone
aroma compound responsible for peppery notes in wines
137
Terpenes
Aromas formed through fermentation that contribute to floral and citrus aromas (e.g. linalool and geraniol in Muscat)
138
Thioles
Aromas formed through fermentation, creating aromas of exotic fruit, cat piss (cooler climates) and/or grapefruit (3MHA, 4MMP, 3MH)
139
Basket Press
('vertical' or 'champagne' press) traditional press suited for small wineries making premium wines, made up of an open structured basket to be filled with grapes and pressure is applied from above. NOTE: smaller press load + more oxidation risks.
140
Cryo-extraction
process of concentrating must by freesing the must/final wine and removing ice from it
141
Inert Gases
chemically inactive gases, meaning it will not react with wine compounds. Used for sanitizing or prevention of oxidation > Nitrogen, Carbondioxide, Argon)
142
MOG
Material Other than Grapes
143
Pneumatic Press
('air bag press') used in medium to large-scale wineries, made up of a cylindrical cage with an air-filled bladder, pushing the grapes against grates on the side of the cage, separating the juice or wine from the skins. Programmed to exert different amounts of pressure and thereby creating different blending components. Oxidation risks are minimal.
144
Pomace
Solid remains of grapes left after pressing
145
RCGM
(Rectified Concentrated Grape Must) processed to only contain the sugar from the grape and therefore neutral in flavours and required I smaller amounts to sweeten the wine.
146
Reverse Osmosis
process of concentrating must for enrichment by eliminating a part of water through specific membranes
147
Stuck Fermentation
the stop of fermentation occuring in case of 1.temperatures rising above 35 C during fermentation 2.stressed yeast due to lack of nitrogen, also leading to the production of undesirable sulfur compounds (e.g. rotten egg smell). It can be prevented by adding nutrients such as DAP (diammonium phophate), thiamine (Vit B1) and nitrogen.
148
Ullage
(Ouillage) headspace of air between wine and top of container)
149
Bentonite
form of clay adsorbing unstable proteins and colloidal colouring matter, with minimal effect on the flavour and texture of the wine. NOTE: wine is lost due to large formed amounts of sediments.
150
Casein
milk-derived protein used as fining agent (must + wine) removing browning from white wines and aiding clarification NOTE: allergen.
151
Centrifugation
rapid process of clarification that spins the wine at high speed, also possibly replacing depth-filtration. Due to costs only practised in high-volume wineries
152
Charcoal
fining agent removing brown colours and some off-odours NOTE: easy on over-fining removing desirable aromas and flavours, option to reduce this is to blend one treated batch with the rest.
153
CMC
(carboxymethylcellulose) cheaper method of (temporary!) tartrate stabilisation, in which cellulose extracted from wood prevents tartrates from developing to a visible size. NOTE: reacts with tannins and causes haze in red wines.
154
Cold Stabilisation
process of removing potassium bitartrate, in which the wine is held at -4 C for 8 days and crystals will be formed (less soluble at colder temperatures) and can then be filtered out. NOTE: fining in advance is needed and no calcium tartrate is removed.
155
Contact Stabilisation
Rapid process (2 hours) of removing tartrates, in which the wine is held at 0 C and potassium bitrartrate is added to speed up the start of crystallisation process.
156
Cross-flow filters
(tangential filters) Form of surface filtration, used to filter wine with a high load of particles of lees very quickly. It allows the wine to pass through the filter while uniquely cleaning the surface (not clogging) of the filter as it works. High investment costs.
157
Diam cork
form of technical cork from recomposed cork particles that have been cleaned and reconstituted with plastic, championed by Diam
158
Diatomaceous earth
(Kieselguhr = silica) filter medium used for depth filtration, especially for very thick and cloudy wine. Used in rotary vacuum filters (oxidative process) or enclosed in filters (possible to flush with inert gas to avoid oxidation).
159
DMDC
Dimethyl dicarbonate (Velcorin), which is used for inactivating Brettanomyces
160
Electrodialysis
Form of tartrate stabilisaton process, in which charged membranes are used to remove selected ions. NOTE: more efficient (energy + costs) and more rapid.
161
Filtration
physical separation technique used to eliminate solids from a suspension by passing it through a filter medium consisting of porous layers that trap solid particles (thus making the liquid clear)
162
Fining
Process in which added agents (proteïns or minerals) attract oppositely charged colloids (unstable microscopic particles), resulting in a larger formed possible to remove by racking or filtration.
163
Finishing
wine preparing to be put in its final packaging, including executing clarification, stabilisatiion and check on dissolved oxygen and sulfur dioxide
164
Flash pasteurisation
method by which micro-organisms are killed by shortly heating the wine to a high temperature (80 - 90 C) and then cooled rapidly, directly followed by bottling process. NOTE: quality risks + premature ageing
165
Gelatine
protein collagen extracted from pork used as fining agent (must + wine) aiding clarification and removing bitterness and astringency in red wine + browning in white wine. NOTE: Easy on over-fining (stripping flavour + character and protein haze).
166
HPLC
High Performance Liquid Chromatography, technology used by wineries. for analysis of technical aspects of the final wine (e.g. pH, dry extract, tartrates + proteins, RS, SO2 and microbial populations) Alternative: FTIR = Fourier Transform Infrared Spectroscopy
167
Ion Exchange
Type of tartrate stabilisation process, in which crystallisation is being prevented by replacing potassium and calcium ions with hydorgen and sodium ions, which will not drop out of solution NOTE: not allowed in all territories as Sodium is not conductive to health
168
Issinglass
protein collagen derived from fish bladders, used as a fining agent to effectively clarify white wines. NOTE: protein haze and fishy smell when over-used.
169
Membrane filters
(cartridges) Filters with pores smaller than 1 micron, used as common form of surface filtration during botteling/packaging, to make the wine clear and microbiolically stable (removing yeast and bacteria).
170
Metatartaric acid
Compound used for tartrate stabilisation, that prevents the growth of potassium bitartrate and calcium tartrate crystals, reducing the need for cold stabilisation NOTE: unstable, esp when stored at high temp = 25-30 C), more suitable for red wine
171
PVPP
(PolyVinylPolyPyrrolidone) an insoluble plastic in powder form used as fining agent, removing browning and astringency from oxidised white wine. Rarely used on red wines.
172
Sedimentation
process of physical clarification, in which suspended matter precipitates and forms a sediment at the bottom of the container, followed by racking or several rackings to separate the wine from it. Cool cellar conditions and time are required.
173
Sheet filters
("plate and frame") Used for depth filtration, removing remaining yeasts at bottling. The speed of the filtering depends on the amount of sheets. Trained personnel is needed
174
Stabilisation
process during winemaking to prevent the forming of undesired effects in the finished wine, including 1.unwanted hazes (protein) 2.deposits in the bottle (tartrate) 3. rapid changes in the wine (microbiological)
175
Hyperoxidation
technique of delibarately exposing white grape must to oxygen before fermentation, mainly to 1.make wines more stable against oxidation after fermentation 2.remove bitter compounds from solids 3.reduce levels of volatile thiols and methoxypyrazines.
176
Appassimento
Method of making sweet wine bij drying the grapes off the vine, using climate-controlled rooms or laid out to dry in the sun. Time of this process depends on the extent of drying required and the speed of it. (e.g. Recioto della Valpolicella and Vin Santo)
177
Icewine/Eiswein
Sweet wine made out of concentrated juice pressed out of healthy late harvested frozen grapes. Also protected labelling terms for which various regulations must be followed by the wine maker. (e.g. Canadian grapes must be harvested <-8 C)
178
Laccase enzyme
Contributed by Botrytis when making noble rot wines, that is capable of oxidising components in grape must and relatively restistant to SO2. When making botrytised wines use of high doses of SO2 and inert gases and chilling is required
179
Noble Rot
Method of making sweet wine involving Botrytis cinerea, made from 1.fully ripe grapes grown in 2.damp climate conditions, allowing rot to develop on the grapes and puncturing the skin by 3.microscopic filaments leaving holes through which 4.water evaporates, concentrating the sugars, acids and flavours like ginger, honey and apricot. (e.g. Sauternes, BA, TBA and Tokaji)
180
Süssreserve
unfermented grape juice used to sweeten the wine, contributing to a grape-juice-like character, and for PDO wines it must come from the same wine region as the wine being made
181
Cordon training
Vines consisting of a trunk and one or two arms (cordons) of permanent wood, usually spur pruned. This form takes longer to establish due to the amount of permanent wood.
182
Vine pruning
removal of unwanted parts of the vine, taking place in the summer and winter, the latter important determining the number and location of buds, thus impacting the potential yield.
183
Spur pruning
short sections of one-year-old wood, cut back to 2 or 3 buds. Can be carried out as cordon training or as head training
184
Replacement cane pruning
canes (longer sections of one-year-old wood) containing 8 to 20 buds, typically laid down horizontally and tied to a trellis for support and positioning. Number of buds left on vine depends on the vigour of the vine, also influencing the number and size of shoots and amount of fruit.
185
Glycerol
Third most abundant part of wine, derived from the sugar in grapes, contributing to smooth texture and to the perception of full-bodiedness and also tasting slightly sweet. Occuring in higher levels in botrytis-affected grapes and wines made by Carbonic Maceration.
186
Phenolics
Compound occuring in grapes (skins, stems and seeds), including anthocyanins and tannins, adding to the astringent mouthfeel (binding with proteins in the mouth) depending on the balance and structure of the wine (e.g. sugar and acidity).
187
Phylloxera
aphid-like insects that feed and and lay eggs on the roots, harming the vines by damaging the roots and thereby reducing the uptake of nutrients and water, making the vines more vulnerable to other bacteria/fungi, reducing growth and yield and eventually leading to death of the vines. Identified in EU in 1863 and 2/3 of the vineyards were destroyed.
188
Grape Moths
Pest organism, propagating several generations per season, damaging the vines by feeding on flowers and grapes creating wounds vulnerable to attack of bacteria and fungi. Most common types are light brown apple (australia), european grapevine and grapeberry (North-America).
189
Bacillus thuringiensis
bacterium used for biologically controlling grape moths by producing substances that are toxic to them.
190
Spider Mites
Insect pests feeding on the surface cells of leaves, leading to discoloration of the leaves > a reduction in photosynthesis > delayed ripening and > a reduction in yields. Thriving in dusty conditions (drougth). Most well-known are Pacific spider mite (California), red spider + two forms of yellow spider (Europe).
191
Powdery Mildew
Fungal disease (Erysiphe necator = oidium tuckeri), overwintering in buds, attacking young, green parts of the vine, causing grey/black patches on shoots, inflorescences and grapes. Also causing grape splitting. Thriving in shady conditions up to 25 C. Most vulnerable are vinifera grapes (e.g. Chardonnay + CS / PN + R are less prone to attack). Spec. treat = early season sulfur spraying.
192
Downey Mildew
Caused by Peronospora, a water mould living within the vine tissue, attacking green parts and causing defoliation (also affecting grapes). Creating yellow 'oil spots' and white fungal growth on underside of leaves. Thriving at 20 C and rainfall (esp warm springs and summers). Spec. treat = drainage + Bordeaux-mixture.
193
Grey Rot
Less begnine form of botrytis cinerea, causing damage to fruit, especially to grapes that are already damaged. When affecting flowers it can stay dormant until véraison. Susceptible GV have tight bunches and thin skins (e.g. Semillon, SB, PN). Spec. treat = Bacillus Subtilis.
194
Bordeaux-mixture
Combination of copper sulfate and lime as treatment for downey mildew, uses since 1880s. Protection only lasts until 20 mm of rainfall. Only option for organic growers, although concerns are about build-up of copper in soil and water.
195
Eutypa Dieback
(Dead arm) fungal trunk disease spread by wind over long distances, causing stunted shoot growth and yellowing leaves, leading to rotten wood. Infection through pruning wounds esp. during rain. Susceptible GV are Grenache, CS, SB. Spec. treat = cutting back 5-10 cm beyond affected parts + Bac. Subtilis.
196
Phomopsis Cane and Leaf spot
fungal disease, thriving in years with cool wet springs followed by humidity and moderate temperatures. Causing whitening of canes breaking off easily and shoots developing brown cracks at their bases. Susceptible GV are Grenache, CS is less prone. Spec. treat = apply of fungicides 3 weeks after budburst + every 2 weeks ico wet conditions.
197
Esca
fungal disease caused by group of organisms in warmer, drier climates, entering through pruning wounds. Creating tiger-striped leaves and spotting inside wood. No chemical control, prevention is best. Spec treat = Bac Subtilis + pruning techniques
198
Pierce's Disease
Bacterial Disease, living in the sap channels of the vines and clogging them, quickly killing the vine. Vines must be tested when establishing. Spread by sharpshooter insects (e.g. glassy-winged sharpshooter in 1980s). Susceptible GV are Chardonnay and PN. Spec. treat= removing vines close to rivers + natural predators (wasp species) of sharpshooters.
199
Grape vine yellows
group of diseases (e.g. flavascence dorée) living in a range of plants including cover crops and vines, spread by vectors causing delayed budburst, drooping postures (shoots do not lignify) and canopy turning yellow or red. Susceptible GV are R + Chardonnay. Focus on prevention. Spec. treat= controlling vectors + bath pruning wood in hot water
200
Fanleaf Virus
(=fanleaf degeneration), causing stunted shoot growth, distorted growth of canes and pale malformed leaves. Susceptible GV is CS. Spread by grafting infected planting material and dagger nematode.
201
Leafrol Virus
Slowing down growth of roots and shoots, fruits ripen later and less carbohydrates are stored. Symptoms are downward rolled and discoloured leaves. Spread by grafting infected planting material + mealy bugs (South-Africa, Argentina, parts of California and Mediterranean) Focus on prevention and natural predators (e.g. ladybugs and lacewings) of mealy bugs.
202
Intracellular fermentation
process of anaerobic metabolism, in which 1.sugar and malic acid inside the grapes are converted to alcohol/ethanol without involvement of any yeast, 2.reducing the malic acid levels by up to 50%, 3.raising the pH and increasing the levels of glycerol and 4.creating distinctive aromas (e.g. kirsch, banana, bubble gum and cinnamon).
