Viticulture and Vinification Flashcards
What is the primary species of vine used for fine wine production?
Vitis vinifera
What is viticulture?
The study of grape growing
What is the first step in the annual vine cycle?
Budbreak
When does budbreak typically occur in the Northern Hemisphere?
March or April
At what temperature will budbreak initiate?
50 degrees Fahrenheit / 10 degrees celcius
What are embryo bunches?
Small green clusters that form on the shoots of a vine by mid-April
How long after budbreak does flowering typically occur?
6-13 weeks after budbreak (depending on the climate)
When does budbreak typically occur in the Southern Hemisphere?
September or October
What happens after embryo bunches form?
Flowering
How long does flowering typically occur?
10 days
Are vitis vinifera vines self-pollinating?
Yes
What does vine self-fertilization lead to?
Fruit set
What is fruit set?
The process in which flowers become fruit and potential fruit size is determined
What is shatter?
When a grape cluster fails to develop into maturity. The grapes fall from the vine and are unusable
What is coulure?
The French word for shatter
When does véraison typically occur in the Northern Hemisphere?
July to September
What does vendange mean?
Harvest
During which months does vendange occur in the Northern Hemisphere?
September to October
Which color of grapes are generally harvested first? Are there exceptions?
White is generally first. Late harvest and botrytized white grapes are often harvested last
What is hang time?
The amount of time grapes spend on the vine
When does véraison typically occur in the Southern Hemisphere?
January to March
During which months does vendange occur in the Southern Hemisphere?
March to April
What factors influence climate?
Expected temperature/rainfall/sunshine/wind
What is weather?
The daily manifestation of climate
What is the difference between climate and weather?
Weather can vary. Climate is relatively stable
In what temperature range do vines thrive?
50-68 fahrenheit / 10-20 Celcius
What is the ideal temperature for vines to thrive?
57 fahrenheit / 14 Celcius
What average summer temperature do red grapes prefer to ripen?
70 Fahrenheit / 21 Celcius
What average summer temperature do white grapes prefer to ripen?
66 Fahrenheit / 19 Celcius
Between which latitudes is grape growing generally restricted to?
30-50 degrees
How are degree days calculated?
Multiply the number of days in each month during the growing season (April 1 to October 31) by the average number of degrees over 50 Fahrenheit for that month.
What is the California Heat Summation Index?
A method to categories climates based on temperature. 5 regions and six categories are based on the number of heat days
What is CHSI Region Ia?
850-1.111 days Celcius
What is CHSI Region Ib?
1.111-1.389 days Celcius
What is CHSI Region II?
1.389-1.667 days Celcius
What is CHSI Region III?
1.667-1.944 days Celcius
What is CHSI Region IV?
1.944-2.222 days Celcius
What is CHSI Region V?
2.222-2.700 days Celcius
What is the minimum number of sunshine hours necessary to support viticulture?
1.300 hours
How many centimeters of rain do vines need?
51-76 cm annually
What is water stress?
A condition caused by too little rain that promotes small berry size and yields. Can lead to total vine shutdown in extreme cases
What effect can too much rain have on a vine?
Dilute fruit quality
Increase risk of fungal diseases
What does terroir mean?
The complete system of the living vine
What is a macroclimate?
The climate of an entire region
What is mesoclimate?
The climate of a specific vineyard
What are some factors that affect mesoclimate?
Aspect (the degree and direction of a vineyard’s slope)
Shelter of a vineyard
What is a microclimate?
The climate around a vine canopy (all parts of the vine above ground)
What are some canopy management techniques that can affect microclimate?
Winter pruning
Leaf removal
Shoot positioning
Trellising
Which soil type produces better wines: low-fertility or rich soils?
Low fertility
What is the relationship between soil pH and grape pH?
Inverse. High soil pH leads to low grape pH. Low soil pH can be a detriment to vine growth
What technique can counteract low soil pH?
Application of lime to the soil
What are some reasons that a producer would use a grape clone?
Disease resistance
Hardiness
Yield
Aromatics
Structure
Color
What is clonal selection?
Cuttings are taken from a single desirable plant
What is massal selection?
Cuttings are taken from a variety of desirable plants within a vineyard
In which region is mass selection popular?
Burgundy
What are some reasons a producer would use mass selection?
Reinforce positive and eliminate negative traits through appropriate selection
Increase genetic diversity
What is a scion?
The upper part of a vine grafted onto a rootstock
After how many years will a newly planted vine need before producing grapes suitable for harvest?
3 years
After how many years is a vine considered mature and stable?
6 years
After how many years are vines typically considered uneconomical?
50 years
Describe cordon-training
Each vine has a permanent cordon that extends from the trunk. Shoots emerge from this can each season
Describe head-training
Each vine has no permanent cordon. Just a head (knob).
Which training method commonly requires trellising?
Cordon-training
Are head-trained vines spur or cane pruned?
Both
Are cordon-trained vines spur or can pruned?
Spur
What is a spur?
A cane that is cut back to two buds
Describe spur-pruning
The upper cane growing from the spur is pruned each winter. The lower cane growing from the same spur will be pruned down to two buds
Describe cane pruning
Each vine maintains one spur and one cane
Who developed the Guyot system?
Dr. Jules Guyot in 1860
What is the Guyot system?
A cane-pruning/head-training system with a vertical trellis on which the canes can be suspended. Each vine has one spur and one two-year old cane
What is the Guyot Double system?
Same as Guyot but supports two canes growing outward apart from each other
What is the Gobelet system?
A spur-pruning/head-training system where the vines are unsupported and form the shape of a goblet.
Where is the Gobelet system commonly used?
Southern Rhône
Southern Italy
What is the Gobelet system called in Italy?
Albarello
What is the Gobelet system called in Spain?
En vaso
What is the Cordon de Royat system?
A spur-pruned/cordon-trained system commonly used for Pinot Noir in Champagne. Similar to Guyot. There is a single spur-pruned permanent cordon extending horizontally from the trunk.
What is the Geneva system?
Spur-pruned/cordon-trained where cordons extend outward from the trunk in a flat U shape
What is Vertical Shoot Positioning?
A trellising system that can be used for both spur- and cane-pruned vines
What is the Tendone system?
Vines are trained upward and overhead along wooden frames or trees so that workers can pass underneath. Vines can be spur- or cane-pruned
What is the Tendone system called in Italy?
Pergola
What is the Tendone system called in Portugal?
Enforcado
What are the four main groups of vine diseases?
Fungal
Viral
Bacterial
Phytoplasma
In which climates are fungal diseases most common?
Warm and damp climates
How does a fungal disease affect vines?
By attacking either the root system or the canopy
What are two of the most worrisome fungal diseases?
Powdery mildew
Downy mildew
How are viral diseases spread?
Through grafting or insects
What is a phytoplasma?
Pathogen similar to bacteria. Symptomatically similar to viral diseases. Can only be spread through grafting or insects
What are grapevine yellows?
Another name for phytoplasmic diseases
When did phytoplasmic diseases first appear in Europe?
Mid-1990s
What is the scientific name for phylloxera?
Daktulosphaira vitifoliae
How does phylloxera affect vines?
Feeds on the roots
Where does phylloxera come from and how to it get to Europe?
Eastern United States. Came to the Southern Rhône in 1863 through imported cuttings
Where is phylloxera not present?
Chile
What soil type is a natural barrier to phylloxera?
Sandier soils
What is the common name for oidium?
Powdery mildew
What is the scientific name for oidium?
Uncinula necator
Where is oidium native to?
North America
In what conditions does oidium thrive?
Humid yet dry conditions
How does oidium affect vines?
Covers all green parts with dusty white mildew. Inhibits bunch development and ripening. Creates off flavors in wine
How can oidium be controlled?
Sulfur and other fungicides
What type of disease is oidium?
Fungal
What is the common name for peronospora?
Downy mildew
What is the scientific name for peronospora?
Plasmopara viticola
Where is peronospora native to?
North America
In what conditions does peronospora thrive?
Warm moist and humid environments
How does peronospora affect vines?
Attacks the green portions. Causes leaves to drop off and limits the vine’s ability to photosynthesize.
How can peronospora be controlled?
Bordeaux Mixture (copper sulfate/water/lime spray)
What type of disease is peronospora?
Fungal
What is the common name for Eutypa Dieback?
Dead arm
What is the scientific name for Eutypa Dieback?
Eutypa lata
In what conditions does Eutypa Dieback thrive?
Mediterranean climates
How does Eutypa Dieback affect vines?
Carried by rain and enters vines through pruning wounds. Stunts shoot growth and releases toxins that can eventually kill the cane. Affects a crop’s yield but not quality
What is another fungus commonly confused with Eutypa Dieback?
Phomopsis viticola
What type of disease is Eutypa Dieback?
Fungal
What is the common name for Esca?
Black Measles
What is the scientific name for Esca?
There is no single species responsible for Esca. It is a complex of fungi
In what conditions does Esca thrive?
Warmer climates. Can be found worldwide
How does Esca affect vines?
Young vines: weaken growth, affect berry development, and discolor leaves. Older vines: causes the trunk’s interior to soften and rot from the inside
How is Esca spread?
Wind
Pruning shears
What type of disease is Esca?
Fungal
What is the scientific name for Black Rot?
Guignardia bidwelli
Where is Black Rot native to?
North America
In what conditions does Black Rot thrive?
Warm and humid weather
How does Black Rot affect vines?
Black spots on the shoots, leaves, and berries. Leads to yield reduction
How can Black Rot be controlled?
Fungicide sparys
What type of disease is Black Rot?
Fungal
What is the scientific name for Bunch Rot?
There is no single species responsible for Bunch Rot. It is a complex of fungi
In what conditions does Bunch Rot thrive?
Warm weather and high humidity
How does Bunch Rot affect vines?
Reduces yield
Adds moldy off-flavors to the wine
What is the difference between grey rot and noble rot?
Both Botrytis. Grey rot breaks down grape skin and causes yeast and other bacteria to rot the fruit. Noble rot is awesome
What type of disease is Bunch Rot?
Fungal
What is the scientific name for Pierce’s Disease?
Xylella fastidiosa
What type of disease is Pierce’s Disease?
Bacterial
How does Pierce’s Disease spread?
By the glassy-winged grasshopper
How does Pierce’s Disease affect vines?
Prevents vines from producing chlorophyll and kills them within 1 to 5 years
Where is Pierce’s Disease found?
Souther US
Mexico
Now moving up California
How can Pierce’s Disease be controlled?
It can’t
What is the scientific name for Crown Gall?
Agrobacterium tumefaciens
What is another name for Crown Gall?
Black Knot
How does Crown Gall affect vines?
Causes tumor (gall) growth on the vine. Essentially strangles the vine and withers or kills the portion of the vine above the tumor
What type of disease is Crown Gall?
Bacterial
In what conditions does Crown Gall thrive?
Colder climates
What is the scientific name for Bacterial Blight?
Xanthomonas ampelina
What type of disease is Bacterial Blight?
Bacterial
How does Bacterial Blight affect vines?
Young grapevine shoots develop dark brown streaks in early spring. They eventually wither and die
How is Bacterial Blight spread?
Rain/Compromised pruning tools
How can Bacterial Blight be controlled?
Hot water treatments
Copper sprays (Bordeaux Mixture)
What causes Leafroll Virus?
A complex of at least nine different viruses
What type of disease is Leafroll Virus?
Viral
What percentage of the world’s grapevine loss is attributable to Leafroll Virus?
60%
How does Leafroll Virus affect vines?
Turns the leaves red and gold. Causes leaves to curl downward. Reduces yields and delays ripening
How is Leafroll Virus spread?
Propogation of infected vines/Insects
What type of disease is Fanleaf degeneration?
Viral
How does Fanleaf degeneration affect vines?
Curtails yields to the point that vineyards must be removed. Also deforms shoot growth: causes poor fruit set: and seedless berries.
How is Fanleaf degeneration spread?
Soil nematodes feeding on roots
What type of disease is Flavesence Doreé?
Phytoplasma
Where did Flavesence Doreé first appear and when?
Armagnac in 1949
How is Flavesence Doreé spread?
Leafhopper insects
Propogation of infected vines
What effect does Flavesences Doreé have on vines?
Delays budbreak
Causes slow shoot growth
Bunches fall off the vine
Berries shrivel
When were genetically modified yeasts first used in North American winemaking?
2006
What are the requirements in the US and Australia for organic wines?
No synthetic treatments
Certain filtration procedures are forbidden
No added sulfites/Use organically-grown grapes
What is Integrated Pest Management?
A holistic view to weed, insect, and disease problems. Allows for targeted use of synthetic products.
Who is credited with inventing biodynamics?
Rudolf Steiner in 1924
What organization internationally certifies vineyards as biodynamic?
Demeter Biodynamic Trade Association
What is vinification?
The transformation of grape juice into wine
What are the two by-products of fermentation?
Ethanol
CO2
Why is sulfur dioxide added to wine?
Prevent oxidation
Prevent bacterial contamination
Ensure rapid fermentation
What chemical is considered a sign of oxidation in finished wines?
Acetaldehyde
What process creates volatile acidity?
Acetaldehyde is converted into acetic acid. Acetic acid reacts with alcohol to produce ethyl acetate
What bacteria turns wine into vinegar in the presence of air?
Acetobacter
Why does hydrogen sulfide form in wine?
Low levels of nitrogen in the must means that yeast can’t work 100%
At what temperature does a must begin to lose flavor and stop fermenting?
95 Fahrenheit / 35 Celcius
What is the relationship between vessel size and fermenting temperature?
Increaseing. Small vessels = slow and cool fermentation. Large vessels = hot and short
Does barrel fermentation need temperature control?
No. The small size of the barrels likely ensures that temperatures do not rise too much
What is bâtonnage?
Lees stirring
What is chaptalization?
Process of adding sugar to the must to increase the final alcohol level and glycerin content of wine
What are spinning cones used for?
Removes alcohol from wine. Often found in the New World.
Describe reverse osmosis
Used to reduce a wine’s alcohol content. Wine is separated into two parts: permeate and retentate. Permeate is distilled to the right alcohol level then remixed with the retentate
What is permeate?
One of the two by-products of reverse osmosis. Contains water and ethanol
What is retentate?
One of the two by-products of reverse osmosis. Contains the wine’s aromatic compounds
Is reverse osmosis legal in the EU?
Yes as of 2009. As long as it does not adjust the wine’s alcohol level by more than 2%
What is acidification?
The addition of either tartaric or malic acid to a must or finished wine to balance a wine
Which acid is preferred in acidification?
Tartaric acid prior to fermentation
What is the chemical by-product of malolactic fermentation?
Diacetyl
What is MOG?
Material other than grapes
What is cold soak?
A pre-fermentation maceration technique that uses high amounts of sulfur dioxide and cold temperatures
What are anthocyanins?
Color compounds found in grape skins. A class of phenolics
What is pommace?
Grape solids
What is remontage?
The process of pumping a fermenting wine over the cap to break it
What is délestage?
The process of draining the fermentation vessel followed by pumping the must back over the cap
What is vin de goutte?
High-quality free run wine
What is vin de presse?
The wine pressed from the pommace after the vin de goutte has been run off. Vin de presse is typically coarser and more tanninc than vin de goutte
What is élevage?
Maturation period of a wine
What is soutirage?
Racking. The movement of wine from one vessel to another to aerate and clarify the wine of its lees.
When in the winemaking process does malolactic fermentation occur?
Either quickly at the end of fermentation or slowly during maturation
What is collage?
Fining. Precipitates solids out of the wine
What are some fining agents?
Egg white
Isinglass
Gelatin
Bentonite
Casein
What is bentonite?
A type of clay used in fining. Good for vegans
What is débourage?
A period of settling after white grapes have been pressed
What is cold stabilization?
A process whereby tartrate crystals are preciptated out of white wine
At what temperature does cold stabilization occur?
25 Fahrenheit / -4 Celcius
What is Süssreserve?
Sterilized fresh grape juice added back to wine to increase its sweetness
Do white wines matured in oak undergo malolactic fermentation?
Often
What is rose blending’s legal status in the EU?
Illegal for wines under PGI level
What is saignée?
Bleeding pink juice from a vessel to concentrate the remaining must for red wine production
What is microbullage?
Micro-oxygenation
What factors affect the flavor imparted by an oak barrel?
Level of toast
Type of wood
What species of tree produce French oak?
Quercus robur
Quercus petraea
What species of tree produce American oak?
Quercus alba
What are the three stages of barrel making?
Chauffage/Cintrage/Bousinage
What is chauffage?
Warming of wood to make a barrel
What is cintrage?
Shaping of wood for a barrel
What is bousinage?
Toasting
Teinturier grapes
Grapes with red skin and red flesh
Caused by natural mutation
Alicante Bouschet
Saperavi
Chambourcin