Viticulture And Vindication Flashcards
Élevage refers to which stage of wine production?
Maturation
Which winemaking technique involves holding the grape must at low temperatures for several days prior to fermentation?
Cold soak
During fermentation, low levels of nitrogen may cause yeast to produce elevated levels of which of the following:
1. Sulfur dioxide
2. Lactic acid
3.Hydrogen sulfide
4. Carbon dioxide
- Hydrogen sulfide- caused by yeast braking down sulfates In to sulfur compounds resulting in rotten egg-like aromas as a fault.
What winemaking process is seen in the picture?
Batonnage
Which compound is produced by Brettanomyces and contributes medicinal and barnyard aromas?
Ethylphenol
What method is used to adjust alcohol after fermentation?
Reverse osmosis
What is the French term of pumping over cap management technique?
Remontage
What compound is a byproduct of MLF fermentation and lends a buttery aroma to the wines?
Diacetyl
What is Fanleaf Degeneration?
A virus caused by nematodes which feeds on the roots of the vines and causes leafs to turn yellow, reduction in canopy and eventually over.time can cause the vine to die.
What is Soutirage?
It is the French term for racking. The action of transferring the fermented wine from one vessel to another to separate it from its sediments.
Why should the best vines have deep roots?
To enable them to stand against harsh weather conditions like frost and drought
What are the requirements for fermentation to take place?
Sugar, yeast, warmth
What does fermentation produce besides alcohol
CO2 and sediments
Why is sulphur dioxide gas often used at an early stage in the fermentation process?
To prevent growth of wild yeast
The presence of a purple rim to a red wine means the wine is
1-3 years old
What are the differences between hybrid and crossed vine?
- Hybrids- are result of crossing two DIFFRENT vine species: V.F with American grape species like cities Lambrusca and Vitis riparia
- Crossed- crossing of two different grape varieties from the same species (V.F)- Pinotage
What is the difference between grey rot to noble rot?
It is the same fungal disease only that grey rot is developed with lack of vaporising conditions to dry the botrytis cinerea to become the desirable noble rot.
What is the Leafeoll virus?
It is a grapevine virus and spread by mealybugs or trough infected plant material. It causes redning and yellowing of leaves as it weakens and shuta down the vine.
There is no cure.
What are downy and powdery mildew and what’s the difference between them?
They are both a fungal disease
Downy- thieves in Cool conditions and develops fuzzy gray or purple costing , yellowing and curling of leaves and eventually reduces qualities yields.
Powdery- thrives in warm conditions and develops a white or grey coating one leaves, shoots and fruit. The leaves may become deformed and fruit maybe discolored
What is Eurypa dieback?
‘dead arm’ a fungal disease effecting woody parts of grapevine and eventually killing it.
