Winemaking Flashcards
What is the grapevine species for Niagara and Concord that has a notable ‘foxy’ aroma?
Vitis labrusca
What is the North American grapevine species that is very winter hardy and great for hybrid grapes? e.g Baco Noir, Triumph d’Alsace
Vitis riparia
What is the grapevine species that is from the Southwest US and used to breed rootstock for grafting and hybridization?
Vitis rupestris
What is the grapevine species that uniquely requires pollination and is native to the Southeastern US? e.g Scuppernong
Vitis rotundifolia
Define ‘cross’
intrA-specific breeding (same species)
Define ‘hybrid’
intER-specific breeding (different species)
Define ‘clones/cultivars’
Different varieties within the same species
What is an example of an exceptionally old vineyard that has been site selected?
1) Clos Vougeot in Cotes du Nuits, Burgundy
2) Clos de la Coulée de Serrant in Savennieres, Loire Valley
Define ‘degree days’
Measurement of total heat over the course of a growing season by adding the high temperatures over 10ºC for the season.
What is considered to be the minimum degree days for viticulture? What factor can influence this?
1100; microclimates allow this number to be lower if the conditions are right
Define ‘frost-free days’
Length of the practical season.
What are some human methods to length the frost-free days?
Wind machines or heaters
Slope in a vineyard can draw cool air down just like water, settling at its lowest point. What is considered the minimum slope best o plant to prevent frost prone areas settling in your vineyard?
5%
What is the ideal relationship between water and vines?
Vines will be slightly stressed throughout the ripening cycle.
What are the 5 primary reasons vines are grated onto rootstock?
1) pests resistance
2) suitability to soil chemistry
3) drainage
4) vigour
5) growth habitat
What common rootstock is a Berlandieri x Riparia cross that is known to be adaptable and produce strong yields but is not suitable in dry soils.
S04
What rootstock the child of Riparia x Rupestris and has low-medium vigour and is suited to deep soils, good drainage and cool climates.
3309 Couderc
What is a Riperia rootstock that has low vigour, suitable to very well drained sites and needs proper fruit yield management?
Riparia Gloire de Montpellier
What is a Riparia x Rupestris cross rootstock that is suited to moist and deeper soils (e.g clay) and has moderate vigour?
Millardet and de Grasset 101-14
What rootstock works well in acidic soils?
Gravesac
What rootstock is lime tolerant?
140 Ruggeri
What rootstock is good for low vigour varieties?
Kober 5BB
In the eyes of a viticulturist, when does the grow cycle begin?
As soon as the grapes are off the vine.
When does pruning of he canes happen?
Over the winter
When does bud-break usually occur in the Northern/Southern hemisphere?
As early as March in Northern hemisphere and September in the Southern hemisphere.
At what point does flowering begin after bud-break? How long does it last?
Between 1.5-3 months later. Lasts up to 2 weeks.
Define ‘hermaphroditic’ in terms of grapevines?
Self-pollinating
When does fruit set / veraison happen occur in the Northern/Southern hemisphere?
July - Northerns
January - Southern
What changes occur during veraison?
Skins soften
Colour changes
Sugars accumulate
How far down do you plant a new vine/rootstock?
~50cm
In temperate climates, what time of year is preferred for planting new vines? Why?
Fall because the surrounding soil has the winter to settle and warm up gradually in the spring.
In Northern climates, what time of year is preferred for planting new vines? Why?
Spring to avoid the possibility of frost damage over the winter and allows for the use of potted vines.
What are potted vines?
Vines that have been raised in greenhouses that have the benefit of a year’s growth before being planted.
What is the different between the brand categories of cane and spur pruning methods?
Cane pruning is where a full cane or more is laid down and spur pruning is when the canes are cut back to a couple of buds on a spur.
Is this an example of cane or spur pruning?
Spur
Is this an example of cane or spur pruning?
Cane
What are some factors that define a growers choice on trellising system? (7)
1) Site
2) climate
3) vigour
4) growth habit of the wine
5) bud viability
6) yield expectation
7) tradition
What are the 3 main types of trellising?
1) Bush vines (no trellis needed)
2) Single or double canopy
3) pergolas
What is the importance of canopy management?
1) Avoiding overgrowth
2) Increasing airflow
3) reduce disease
4) better coverage of spraying
5) sun exposure
6) protection from wind, machinery and the weight of the grapes themselves
Describe the signs, effects, conditions and treatment for downy mildew (plasmopara viticola).
Signs: oil spots on the vine leaves or reddish-purple mummified berries.
Effect: reducing photosynthetic potential
Conditions: temperate, wet and humid
Treatment: synthetic chemical sprays or copper sulphate
Describe the signs, effects, conditions and treatment for powdery mildew (uncinula necator).
Signs: white-powder substance on any part of the vine
Effects: prevents further growth of organs, grapes dry out and crack open, overwinters on the vine and can cause rapid outbreaks in the spring
Conditions: warm / hot, humid
Describe the signs, effects, conditions and treatment for botrytis cinerea.
Signs: dry, shrivelled berries
Effects: can be positive if it is followed by dry conditions and grapes see sugar concentration but if its followed by wet weather, it can ruin the whole crop
Treatment: good airflow and synthetic sprays
What is the pest that carries Pierce’s Disease via bacteria? How is it managed?
Glassy Winged Sharpshooter; careful scouting and aggressive spray programs
Describe the signs, effects and treatment for black rot (guignardiaa bidwellii).
Signs: small brown spots on the leaves, black elliptical marks on the shoots
Effects: grape turns black and mummified, results in large loss of crops
Treatment: microscopic sulphur
What part of the plant does phylloxera attack? What is the only prevention?
The roots; grafting onto American rootstock
Why is Chile seemingly safe from phylloxera?
Strict important laws and natural geographic boundaries.
What pest may not have entirely damaging effects on a grapevine, but does reduce the overall photosynthetic potential of it?
The European Red Mite
What animal wears a mask and loves snacking on grapes?
What are some prevention methods for birds in a vineyard?
Scare tactics, nets, and falconry.
Name the 6 general types/categories of equipment found in a vineyard.
1) Tractors
2) sprayers (tow-behind or hand-held)
3) Hedger (single or doubles-sided)
4) Leaf remover
5) Soil implements (harrows, plows, sub-boilers, and tines)
6) Under-the row (cultivators, mowers, blades)
Two most prominent types of sugar in grape.
Glucose and fructose.
True of False: Tartaric and acetic acid are the two main acids found in a ripening grape.
False: tartaric and malic
What acid decreases first during ripening?
Malic
In hot climates, what often has to happen with acidity levels in wine processing? Why?
Addition of acid because the grape ripens quickly and acid levels fall quickly.
In cold climates, what often has to happen with acidity levels in wine processing? Why?
Malolactic or de-accidification due to high ratio of malic acid.
What is pH a measure of? What influences does it have on the wine?
The acidity or basicity of a solution. It influences the colour, mouthfeel, balance and development of the yeast and bacteria.
What compound includes tannin and anthocyanins? What are they responsible for?
Polyphenols; colour in a wine.
As acid level drops, pH level ___________.
Increases
What are the benefits and draw-backs of hand-picking grapes over machine harvesting.
Hand picking is more gentle, gives whole clusters and can selectively take or leave grapes at their optimal point. Machine harvesting is must more efficient but it can damage berries in the aggressive process.
What can be done to slow down oxidation and preserve acidity of berries when machine harvesting?
Pick at night.
What is the standard wine yeast called.
Saccharomyces cerevisae
What does yeast need to perform its task of converting sucrose to ethanol?
Nitrogen, carbon (fermentable sugars), oxygen, various vitamins and minerals.
How is sucrose broken down into glucose and fructose in order to be fermentable?
An enzyme called Invertase.
What are some bi-products of fermentation?
Co2, volatile acidity, acetylaldehyde, esters.