Viticulture & Vinification Flashcards
What is Vendange?
Harvest
What are the Italian and Spanish names for the Gobelet System?
Italian: Albarello
Spanish: En Vaso
- It is the simplest form of spur-pruning / head training
- An ancient technique common in Southern Rhône and southern Italy
- The vine, unsupported, resembles a goblet
- Each year’s fruiting canes extend from the spur-pruned shortened arms atop the trunk
What is the Bordeaux Mixture?
Spray of copper sulfate, water, and lime
What happens in the vineyard in February? (in the Northern Hemisphere)
The vine starts “weeping” or “bleeding” watery sap from pruned canes
When does budbreak occur?
March / April (northern hemisphere)
- First small shoots and leaves will break through buds left intact by winter pruning
- The vine is vulnerable to frost at this time
- Foliage continues to develop through early spring
- Small green cluster bunches form on the shoots by mid-April
When does flowering occur in the vineyard?
6-13 weeks after initial budbreak
- Embryo bunches bloom into small flowers for about 10 days
- The self-pollinating grapevine begins the process of fertilization which leads to fruit set
- Extremely susceptible to damage from cold, frost, and wind during this time
- Pollinated embryo bunches grow into true grape clusters during fruit set
- Fruit set usually hovers around 30%; the remaining embryo berries “shatter”, falling from the cluster
- Berries enlarge through July, remain hard, high in acidity, low in sugar
When does véraison begin?
August (northern hemisphere)
- Grapes begin to truly ripen
- Sugars are moved from the leaf system to the fruit
- Grapes soften and change color
- May not evenly affect a whole bunch (Some varieties, ex. Zinfandel, are characterized by extremely uneven ripening)
- Cane ripening occurs in tandem with véraison (stems on each shoot being to lignify, accumulating carbohydrates to sustain the plant through winter)
When does vendange occur in the vineyard?
August-November (northern hemisphere)
- Harvest begins as early as late August
- White grapes are generally harvested before red grapes
- New World winemakers have greatly advanced the idea of complete physiological ripeness (concept of ripeness comprising of not only must weight and pH, but ripening of tannin and other phenolics, condition of berry and its pulp, and seed lignification)
In the vineyard, what happens after harvest?
- The vines lose their leaves in Autumn and enter a period of winter dormancy
- Fertilization may be applied in the Autumn after harvest
- Vines will be pruned over the winter to prepare for next year’s growth
What is the required average summer temperature for red grapes?
70ºF / 21ºC
What is the required average summer temperature for white grapes?
66ºF / 18.89ºC
The vine requires ______ mm rainfall annually.
500-760mm (20-30 inches)
What is water stress?
A condition that promotes smaller berry size and yields, but will lead to interrupted ripening and complete shutdown of the vine if stress is too severe
*Caused by too little rain
What are wind machines often used for in the vineyard?
Used to fight frost
*Mixes colder, settled air near the ground with warmer upper air
High soil pH contributes to (higher/lower) acidity in grapes.
Higher
*high soil pH is common in limestone-rich soils
Describe spur-pruning.
- The upper cane grown from a spur is removed during winter pruning
- The lower cane growing from the same spur is cut back to two buds, which creates a new spur
- Each spur will produce two fruiting canes each year with one becoming the following year’s spur
Vitis ______ was used for grafting because it was resistant to phylloxera.
(Vitis) Riparia
What is the full name of Phylloxera?
Daktulosphaira Vitifoliae
*Originally called phylloxera vastatrix
Phylloxera feeds on what part of the vine?
Roots
How do fungal diseases manifest?
As mildew or mold
How are viral diseases spread?
Through grafting or by insects
How is Phytoplasma spread?
Through an insect vector or rootstock grafting
Today, biodynamic viticulture is personified by ______?
Nicolas Joly
Most yeasts do not act below ______ºF and die above ______ºF.
- 50
2. 113
What is stuck fermentation?
A disastrous and sudden shutdown of yeast activity
*Less of a problem in the age of temperature control
During reverse osmosis, the wine is separated into ______ and ______.
Permeate: contains water and ethanol; later distilled to a proper level before being recombined with the retentive at a lower percentage of alcohol
Retentate: the wine’s aromatic compounds
In 2009, reverse osmosis was again legalized in the EU provided the level of alcohol is not adjusted by more than ______%.
2%
Name the two acids that may be used for acidification.
Tartaric acid and malic acid
*Tartaric acid, added prior to fermentation, is preferred
What is délestage?
The fermentation vessel is fully drained, then pumped back over the cap in the fermentation vessel
What is bentonite?
A type of clay used for fining
What is the name(s) of the tree(s) used to make French Oak barrels?
Quercus Robur and Quercus Petraea
What is the name(s) of the tree(s) used to make American Oak barrels?
Quercus Alba
What are the tree stages of making a barrel?
- Warming / chauffage
- Shaping / cintrage
- Toasting / bousinage
- light toast promoted the most extraction of wood tanning
- heavy toast promotes more spicy, smoky aromas
In what type of conditions does Powdery Mildew thrive?
Humid, yet dry conditions
- Rainfall is detrimental to the survival of its spores
- It prefers densely shaded canopies and overcast weather
What happens if the vine is infected by Powdery Mildew after fruit set?
Berries will struggle to achieve véraison and reach full size
What happens if the vine is infected by Powdery Mildew before flowering?
Yields will be reduced
A vine is considered mature by its ______ year.
6th
- Shoot growth and the vines annual yield stabilize
- The root system will grow to maturity by the 10th year; poorer soils will slow the growth
What are clones selected for?
Disease resistance, hardiness, yield, aromatics, structure, color
Soil acidity (high/low pH) can be a deterrent to viticulture.
Low pH
What is the agent of Downy Mildew?
Plasmopara Viticola
Powdery Mildew has spread worldwide, but is native to ______.
North America
What is Oidium?
Powdery Mildew
What is Peronospora?
Downy Mildew
How did Downy Mildew get to Europe?
On American cuttings
*Spread rampantly through Europe in the early 1880s
Name the fungus that causes Eutypa Dieback.
Eutypa Lata
- Common in Mediterranean climates
- Spores are carried by rain
- Enters the vine through pruning wounds
- Difficult to control
What happens to vines infected by Eutypa Dieback?
- Stunted shoot growth as the fungus releases toxins
- Affected canes may eventually die – the “dead arm”
- Has a drastic effect on yield
- Does not lower the quality of the crop
Phomopsis Viticola is a disease similar to ______.
Eutypa Dieback
*Also a fungus
How does Esca affect young vines?
- Weakens growth
- Affects berry development
- Discolors leaves
- a young vine may suddenly die in hot weather - Esca is a fungal disease
- Result of complex of fungi rather than a single organism
- Also known as Black Measles
- Thrives in a warmer climate, but exists worldwide
How does Esca affect older vines?
- Affects the wood
- Causes the interior of the trunk and arms to soften and rot from the inside
- Mature, Esca-infected vines will rarely live past 30 years of age
- Exacerbated by rainfall and can be spread by wind or pruning shears
When and how did Black Rot spread to Europe?
It spread with the importation of Phylloxera-resistant rootstocks in the late 1800s
Name the fungus that causes Black Rot.
Guignardia Bidwelli
- Originates as a black spot on the vines’ shoots, leaves, and berries
- Yield reductions can be disastrous if unchecked
- Can be controlled through fungicide sprays
- Native to North America
How does Leafroll Virus affect the vine?
- Causes reduced yields and delayed ripening
- Shows red, gold colors on leaves in the Autumn, along with a characteristic downward curling
- Currently incurable, but will not kill the vine
How is Leafroll Virus spread?
Spread through propagation of infected vines or by an insect vector such as mealybug
- Infected vines are not always removed
- Caused by a complex of at least 9 different viruses
- May be responsible for as much as 60% of the world’s grape production loss
What is bentonite?
A type of clay used for fining
Describe dual-trunk training.
Growers train two separate trunks on the same vine in parallel, just an inch or two apart, from the ground up
- This is used throughout Washington State
- Vines are particularly susceptible to severe crown gall affliction after a hard freeze. With two trunks, the chances of losing an entire vine canopy is halved
