Between which degrees latitude does the vine thrive?
30-50
What are the vine’s 3 major nutritional needs?
Nitrogen, Phosphorous & Potassium
What are the vine’s 6 minor nutritional needs?
Boron, Copper, Iron, Magnesium, Manganese & Zinc
Describe the main components of a vine’s yearly cycle for the following periods: Dec-Mar, Mar, May, Jul, Aug, Sep-Oct, Oct & Nov
Dec- Mar
- Pruning
March
- Bud break
- Shoot growth
May
- Flowering and berry set
July
- Green harvest
August
- Veraison
Sep - Oct
- Clusters ripen & mature
Oct
- Harvest
Nov
- Leaf fall
Describe the main effects the river has on temp and weather patterns
Moderates temperatures by equalising diurnal and seasonal temp swings.
Prevents spring frosts and fall frosts.
Describe the formula/process for photosynthesis
C02 + H20 —(light)—> Sugar + 02
What is the optimal temperature range for photosynthesis?
20-30 degrees
What is the minimum temperature required for photosynthesis?
10 degrees
Which part of the plant does the gas exchange take place?
Small pores on the leaf called stomata
What is it meant by a plant sweating?
The external transpiration of water vapour from the stomata
Above what temperature does a vine shut down?
35 degrees
What is phylloxera? Where did it come from? How does it affect the vine?
A small insect, native to the USA. The insect injects saliva into the roots with each bite and Vitis Vinifera can’t heal over these bite wounds allowing bacteria and fungi to enter and rot the root.
What was a benefit of phylloxera with regards to replanting vineyards?
- Vineyards were replanted in rows (layering was the previously preferred choice of propagation)
- There were now parcels of single varieties (previously lots of different varieties were planted together)
- Better clones and more suited varieties could be planted
What is powdery mildew? What is it AKA? Where is it from? How does it affect the vine?
- Fungal disease, AKA oidium.
- Native to North America
- Blankets the vine with thick white filaments which can reduce yields, retard pigment, stunt cluster growth and cause off-flavours.
What is downy mildew? What is it AKA? Where is it from? How does it affect the vine?
- Fungal disease, AKA Peronospora.
- Native to North America
- Germinates in warm humid weather
- Attacks leaves and stems first with oil spots and then with white cotton filaments causing the vine to lose its leaves and prevent/stop berry ripening
What is the Bordeaux Mixture? Who invented it and what does it do?
- A copper sulphate application
- Alexis Millardet
- Combats fungal attacks
What is Botrytis Cinerea? What does it do to the grapes and what weather conditions are required for its development? What is the issue if the weather stays too cool?
- Fungus that attacks grapes high in sugar content
- Mold penetrates the skin, desiccating the berries and concentrating sugar and flavour compounds
- Cool, moist mornings need to be followed by warm, dry afternoons
- Grey rot can form if it stays too cool which results in off-flavours and reduced yields.
What is coulure? How is it caused?
- A vine problem when cloudy, cold/wet weather at flowering leads to poor fruit set
- A lack of carbohydrates within the vine causes the stems to shrivel and shed young berries, reducing yields
What is the cordon training method? What is the difference between single and double?
- Vines are pruned to 1 or 2 lateral cordon arms that are tied to a support wire (permanent wood)
- Each arm has 5-7 buds
- Renewal spurs (2 buds) are permitted for eventual arm replacement
- AKA spur pruning
What is the eventail training method?
- Vine fanned out on the trellis
- Pruned to 4 or 5 short canes with 5-6 buds each
What is the gobelet training method?
- Vine kept low to the ground with no stake/trellis
- Pruned to 5 or 6 short spurs that form a bowl shape around the trunk
What is the guyot training method? What is double guyot?
- Vine pruned to 1 long temporary cane containing 6-10 buds
- A renewal spur (2 buds) will form shoots that replace the cane next year
- Double guyot employs 2 temporary canes spread in opposite directions
- AKA rod & spur pruning
Briefly describe the 10 stages of dry white wine production
1) Grapes harvested & pressed
2) S02 added to prevent microbial spoilage, browning & oxidation
3) Must settles for 12-24 hours to remove gross particles (debourbage)
4) Acid/sugar adjustments
5) Clear must moved into fermentation vat and ferments at 16-20 degrees
6) Wine is racked (can be more than once) off gros lees and sulfur levels adjusted again for microbial reasons, browning issues or to block MLF.
7) MLF or sur lie aging optional
8) Wines are blended before or after ageing
9) Wines are clarrified (centrifuge, filtering, fining)
10) Wines are cold stabilised
How does the process of fining work?
It clarifies wine working on the principal of +ve and -ve charges attracting.
i.e. bentonite bonds with proteins, egg white bonds with tannin and casein bonds with tannin and acid
