Viticulture Flashcards
Organic viticulture
Farmed vs. produced
No synthetic fertilizers, pesticides, etc
ie: National Organic Program
Biodynamic viticulture
*** Organic plus tasks timed with phases of moon.
**
- Described as “spiritual science”
- Practices such as pruning etc done according to movement of moon.
- Manure used as fertilizers
- No synthetic chemicals
- Goal is to align all the forces of nature
ie: Demeter Certified Biodynamic
Sustainable viticulture
Considers emissions, resource consumption costs, etc. Sustainable farming reduces impact on ecosystem and results in healthier vines.
ie: Certified California Sustainable Wine growing
Dry farming
Growing grapes without adding additional water
common in many regions in California
Macroclimate
Climate of an area, such as a wine region
Mesoclimate
The climate of a vineyard
Microclimate
The climate around a single vine
Degree days
Difference of a day’s average temperature over 50F for all days during the growing season.
1500 minimum to ripen grapes
2500 degree days or less (Riesling, Pinot Noir)
2501-3000 degree days (some Cabs)
3001-3500 degree days (Cabs, Merlot, Grenache, Zinfandel)
3501-4000 degree days (Dessert wine)
4000+ (Table grapes, raisins)
Climate moderators - Altitude
In warm to hot growing areas, increased elevation provides cooler temps to help slow grape ripening and produce more balanced wines. With every 100 meters of elevation, temps drop by one degree.
ie:
Argentina/Chile
Mendoza - vineyards at 1400-6000 ft
Salta - vineyards at 5100-10000 ft
Climate moderators - Dinural shifts
Key to a high quality wine in warm area - allows grapes in warm climates to ripen during the day, and rest/preserve essential acidity at night.
Napa, Sonoma, Paso Robles, Australia (Clare Valley GI), Argentina (Uco Valley)
Climate moderators - Rainshadow
Poor weather is blocked by mountain and creates one side of dry warm weather.
Chile - Coastal Range blocks cool, moist air from Pacific
Washington - Cascade mountains
Climate moderators - Wind
Wind can cool a growing region if originating over cool ocean waters or lend warmth and dry air if originating from a desert to help prevent mold and rot
Rhone Valley - mistral winds helps prevent mold
South Africa - Cape Doctor
Chile - Humboldt current brings cool air
Napa/Sonoma - Petaluma gap
Climate moderators - sunshine hours
Vineyards planted on slops facing equator get the most sunshine hours - necessary in cooler climates like Germany, Burgundy, and Piedmont.
Cimate moderators - bodies of water
Can help mitigate extreme temps - water cools hot climates and warms up cool climates. it also reflects sun onto vines
Germany - Mosel river reflects sun
Sonoma/Napa - Pacific ocean cools region
Rootstock
- The part of the grapevine planted directly in the soil
- Created by crossing varities from different American species
- Known for high resistance to phylloxera
- Bred for adaptability to climatic stress, water availability, and various soils
- Rootstocks must have a SCION grafted onto them to complete the vine
- In regions with no phylloxera, vines grow on their own roots, not rootstock.
Parts of the grape vine
What is the cane?
A vine SHOOT or stem that has turned from green to tannish brown and has become hard and fibrous.
Shoots turn to canes in the fall to withstand the winter
Will ultimately be pruned back
What is the canopy?
A mass of leaves and SHOOTs of a grapevine.
Usually trained by grower to grow in a specific way (ie: bush, trellis, umbrell)
Shades the grape clusters
What is a cordon?
A permanent woody arm that is trained horizontally from the trunk of the vine often along a trellis wire
Supports the grapes and clusters
What is a shoot?
- A tender new green stem that grows from a bud on a vine.
- Shoots emerge from the permanent woody arms of a vine’s trunk
- Will ultimately sprout leaves and tiny clusters of flowers tht will be fertilized to become grapes.
What is the scion?
- The above ground portion of a grafted vine
- The scion is grafted onto the rootstock
- Th scion is the GRAPE VARIETY grown by the plant
Hybrid
2 varieties of different species (ie: vitis vinifera & vitis labrusca). more resilient to mold and phylloxera.
ie: Cayuga, Seyval Blanc
Crossing
A grape variety created by crossing 2 varieties of the same species
ie:
Cab Sauv (Cab Franc and Sauv B)
Pinotage (Pinot Noi & Cisault)
Scheurebe (Riesling & Silvaner)
Clones
To propagate a group of vines from a “mother vine” with desirable characteristics such as resistance to disease and berry size etc…
Relates to plants of same species and variety
Over the years clones can evolve and see genetic mutations
Clones can produce wine that tastes very different, even if from same terroir.
ie: Sauv B has very few clones, Pinot Noir has hundreds
Life cycle of a vine
Bud break - end of March/early April
Early growth - early May, shoots lengthen and tiny flowers appear
Fruit set - flowers pollinate themselves and grow into berries
Veraison - berries begin to soften/swell and change color
-Hangtime - the length between flowering and harvest
-Maturity - physiochemical changes within the cells and pulp of grape - begins at veraison. Phenolics vs sugar ripeness
Harvest - end of Aug through Oct
Dormancy - November/December vine loses leaves and goes into dormancy
Pruning - process of gentle cutting back vines while they are dormant during the winter. Whatever is left is the basis for next year’s crop.
Vine architecture
How vines are laid out.
Vineyard aspect
The direction the vines face, slope and sun exposure. Resulting in characteristics of finished wine that are exposed to heat and light at different times of the day.
What is cordon training? (vine training)
Use support for growth. By lifting up vines and spreading leaves among wires for photosynthesis. Meanwhile grapes can hang freely, get sunlight, and good air flow which prevents mold/rot.
What is head training? (vine training)
Also known as goblet/bush.
Common in old vineyards where vines grow out of the soil like bushes. Leaves naturally shade the grapes.
Grafting of vitis vinifera onto vitis labrusca rootstock
Done to combat phylloxera. Indigenous vine species were tolerant to phylloxera so all vitis vinifera were grafted onto American rootstocks. 1870-1900.
Pierce’s Disease
Bacterial disease caused by Xylella fastidosa. Lives in the water conducting system of a vine and spread via insects such as the Glassy Winged Sharpshooter.
Yield
A measure of how much a vineyard produces
Very high yields usually associated with low quality and low yields associated with high quality but not always the case.
How is yield measured?
In Europe/rest of world: hectoliters per hectare
In US: tons per acre
Because vines in modern vineyards are spaced closely or far apart, more accurate measurement is pounds or kilos per vine
How much is 1 ton per acre in hectoliters per hectare?
1 ton per acre = 15 hectolitres per hectare
Measuring and converting yield (metric/standard)
Measured in:
Tons of grapes per acre
Hectoliters per hectare
Pounds or kilos per vine
How many acres is 1 hectare?
2.471
How many pounds are in a ton?
200lbs
How many liters/gallons are in one hectolitre?
100 liters
26 gallons
How many fluid ounces are in a liter?
33.8 oz
What is phenolic ripeness?
Phenolic ripeness - change in grapes tannins, seeds, skin, and stems. Often trails sugar ripeness.
What is sugar ripeness?
Sugar ripeness - breakdown of acids and accumulation of sugars in the berry.
Night harvesting
Picking grapes when they are cooler helps concentrate flavors and aromas. Keeps sugar levels more stable. Especially helpful for whites and roses.
Decisions in a vineyard - what is vine spacing?
Vine spacing - closer spaces means more competition for nutrients which is good - slows growth, limits yield, and increases balance. 3,000 vines per acre considered tight. Spacing is widening up again in Cali given droughts.
Decisions in a vineyard - what are vineyard passes?
Selecting clusters that are ready to be harvested and leaving behind the underripe grapes til ready.
Decisions in a vineyard - what is green harvesting/cluster thinning?
Removing grape clusters from a vine in order to enhance ability of remaining clusters to ripen fully. This is done several times during growing season, usually right before veraison.
