Extra-curricula Flashcards
What are the 3 key practices to express terroir in wines?
- Timing of phenology
- Water deficit
- Moderate to low Nitrogen
Source: Presentation ‘Interactions of climate, soil and grapevines on wine and terroir’ by Kees van Leeuwen, professor of viticulture at Bordeaux Sciences Agro, and Bordeaux University’s Institut des Sciences de la Vigne et du Vin
Why is timing of phenology important in producing quality fruit (and thus in expressing terroir)?
To achieve high terroir expression, precocity of the grape varieties should match the local climatic conditions, so as to obtain full ripeness at (not before) the end of the season: 10SEP-10OCT in the Northern Hemisphere.
Grapes should not ripen early in the season, because quick fruit ripening in warm conditions limits aroma synthesis.
Grapes that would not attain full ripeness are too acidic, with low sugar and little aroma development.
Why is a water deficit important in producing quality fruit (and thus in expressing terroir)?
Water deficit results in higher quality fruit, because it induces:
- Early shoot growth cessation
- Reduced berry size
- Lower malic acid
- Higher Anthocyanins
Why is moderate to low nitrogen important in producing quality fruit (and thus in expressing terroir)?
Moderate to low nitrogen results in higher quality fruit as a result of:
- Lower vigour, yield and especially berry weight
- Lower acidity
- Higher sugar and Anthocyanins
What is climate?
The annual weather pattern of an area averaged over several decades
Why do they use Chardonnay and Pinot Noir in some continental regions
- They are early-ripening varieties
- In Champagne, Northern regions of Germany and British Columbia there’s long day length but temperatures drop more rapidly in autumn
- => shorter growing season
- => less sunlight and warmth available to the vine at the end of the growing season.
How many Growing Degree Days (GDD) in Amerine Winkler Category I
Below 1370
what is the effect of temperature on photosynthesis?
In cool temperatures, the rate of photosynthesis slows.
What is soil profile
Reveals the different structural and textural soil types
Reveals the depth of the layers
Reveals if there are any drainage or root barriers in the soil
The best fruit comes from
Densely planted, small vines growing on infertile soils.
At what temperature is wine dormant
Below 10 C
When is the growing season in the northern hemisphere?
April to October?
What is Granite
Igneous rock, formed from magma. extremely hard and dense but still free draining.
When is a climate continental?
large difference between the average mean temperature of the hottest month and the coldest month.
explain photosynthesis
Sunlight
H2O Glucose
Chlorophyl Sucrose
CO2 Fructose
Vines grow best on soils with ______________ fertility.
low
What is Aspect
- the direction a vineyard slope faces
- an important charerteristic of a vineyard site where more or less exposure to sun is required
Explain freeze injury to dormant vinifera wood :
- begins at -15°C
- serious at -20°C
- can be fatal at -25°C
unless the vine is insulated by snow or earth pushed up around the vine
EU zone B : What is the acid adjustment (tartaric)?
-1 to + 2,5 g / L
Aeration is affected by
Capacity of the soil to drain effectively.
Canopy climate is called
Microclimate
Temperature _____________ with every 100 meter rise above sea level (altitude–.
Decreases by 0.6 degrees Celsius
What pH grape vines cant tolerate, why
pH bellow 5, aluminium becomes available which poisones the plant.
What are the advantages of sandy or gravelly soils?
- have very good drainage, lower water-retaining capacity
- encourage a vine to grow longer roots which search for water
- benefit from more consistent water levels
- warm up more quickly in spring
- are generally warmer than clay soils
Name some typical moderate climate regions
Bordeaux, N. Rhone, Rioja, Piemonte, Toscana, Coonawarra,, moderate parts of Napa and Sonoma.
Name some soil Micronutrients
Boron
Manganese
Copper
Iron
Molybdenum
Zinc
Cobalt
Chlorine
Silicon
EU zone CII : enrichment may not rise the total alcohol to more than?
13 %
Why are isolated hills ideal vineyard site?
Name 2 renowned hills
- there are no big currents of colder air flowing down from the main hills.
- Burgundy’s hill of Corton (Aloxe-Corton), Montagne de Reims (Champagne)
Limestone rich soil tends to have high pH which inhibits the uptake of iron and other micronutrients and can increase the risk of what
Chlorosis
EU zone A : What is the acid adjustment (tartaric)?
-1 to 0g / L
What is the average mean temperature during the growing season for hot climate?
over 21 °C
What is sulfur?
- S
- macronutrient
- Essential constituent of some amino acids and enzymes.
How can you produce quality fruit in fertile soils?
dividing the fertility between a larger number of shoots
create bigger vines
lower density planting
EU zone C : What is the amount of natural alcohol?
9 %
What regions are in EU region B
Baden, Loire, Champagne, Alsace, Austria, parts of Romania, most Czech Republic
What regions are in EU region C 1b
Hungary, Trentino-Alto Adige
Regions with Granite soil
Baden
Northern Rhone
Grapevines cannot tolerate soil pH below
why?
- 5
- alluminium becomes available to the plant
- it poisons the plant
What is good soil structure?
- It is where the particles form stable crumbs of 1 - 5mm in diameter.
- there must be high to moderate organic matter content (3 - 10 %)
Regions with Limestone soil
Central & eastern Loire
Piedmont
Northern Spain
Burgundy
Limestone Coast in S Australia
Organic content is formed from
Animal remains broken down by beetles, mites, earthworms, fungi and bacteria
What is lighter soil?
- high sand or gravel content
- more free draining
Name some typical warm climate regions
South Rhone, Douro,, McLaren Vale, Paarl
Maritime climate is ideal for what kind of wines? Give also examples.
medium-bodied wines with moderate alcohol levels e.g. red and white Bordeaux, Muscadet, Rias Baixas, Vinho Verde and South of England.
What is the danger of soil compaction?
- can lead to poor rain infiltration
- reduced drainage, aeration, root penetration
At what temperature is optimal vine growth
22-25 C
What kind of wines and what region are best in Amerine Winkler Category II
Premium medium bodied red wines. Regions include Napa Valley, Bordeaux, North Rhone.
What type of wines are often produced in warm climate?
Often fortified wines such as Port of Liqueur Muscat
How can the close proximity of forests be disadvantageous?
- they cool the mesoclimate in warm weather and increase humidity
- they can harbour large flocks of birds which feed on and damage grapes
EU zone C : What is the acid adjustment (tartaric)?
-1 to + 2,5 g / L
zone CIIIb => 0 to + 2,5 g / L
What is Loam
Balanced mixture of clay, silt, and sand. Combine nutrient holding abilities of clay with good drainage capabilities of sand.
Soil fertility (its chemical and physical characteristics) is influenced by
- Soil texture
- Soil structure
- Organic matter content
- Mineral content
- Availability of air and water
- Level of acidity/alkalinity
How many Growing Degree Days (GDD) in Amerine Winkler Category III
1650-1930
Name some typical hot climate regions
San Joaquin Valley.
What increases equally with the vine’s metabolism?
Its demand for sugars.
Why do vines not grow well on poorly drained soils?
- they are cooler
- they take longer to heat up in spring
- they can restrict root growth
- leading to reduced resistance to drought
- increased risk to mineral deficiency
- reduce the bearing capacity of a soil causing problems when machinery passes
What is the photoperiod?
daylenght
Used to improve soil structure, reduce dispersion of surface soil, minimizes swelling of sub-surface soils, thus improving permeability and aeration
Gypsum (CaSO4)
EU zone B : What is the acid adjustment (tartaric)?
-1 to 0g / L
What is the advantage of an eastern aspect?
- When a vineyard faces the rising sun, the sun’s rays are scattered less in the morning, when the earth has cooled overnight and the dust has settled.
- Many of the best vineyard sites face east.
Which ocean currents create cooling mists and fogs and cool down temperatures?
Pacific Ocean current (Calif.) Humboldt Current (Chile--
Vines grow best on soils with low fertility. Why?
- Restrict canopy growth
- Are stony and well drained
When is a site considered unsuitable for vine culture qua min. temperature?
- if its temperature falls below -20°C more than once every 20 years
- if the mean temperature for the coldest month is less than -1°C
why does growths slow above 25 ° C?
The vines metabolic needs increase faster than its ability to photosynthesise sugars.
pH should be increased above 6.5 using what
Calcite (Calcium carbonate); Magnesite (Magnesium carbonate) or Dolomite (mix of both)
What allows the production of high quality wine in areas as California and Chili that would otherwise be too hot?
The Pacific Ocean current (CA– and the Humboldt Current (Chile–) create cooling mists and fogs and cool down temperatures
Organic content is composed of
Sugars
Starches
Cellulose
Nitrogenous compounds
Mineral matter
PH for neutral soil
pH of 7
Soil acidity is measured by the pH scale which measure what
concentration of hydrogen ions in the soil solution
Sandy soil in high rainfall area will be deficient in which nutrients
Potassium, Calcium, Sulfur
Can derogations be obtained from the EU-zone stipulations?
- under exeptional conditions
- e.g. enrichment of up to 4,5% abv is permitted in zone A in particularly poor years
Maritime climate is charachterised by :
(temperpature, rainfall, grape berry ripening period)
- low anual range of temperature (warm summers, mild winters)
- relativaly high rainfall
- => extra cloud cover
- reasonably long grape berry ripening period with moderate temperatures.
Why does the GDD-system work not work adequately in e.g. Australia?
- Because temperature variability, sunlight, humidity are less correlated with temperature then in California .
*
Why is sunlight essential to all plants?
- It is the energy source for photosynthesis
- It increases the temperature of the environment
What is the average mean temperature during the growing season for moderate climate?
16,5 to 18,5 °C
Regions with Chalk soil
Champagne
Jerez
When is a climate maritime?
small difference between the average mean temperature of the hottest month and the coldest month.
What is the disadvantage of a loam soil?
disadvantage : rich, loamy soils can encourage too much vegetative growth and shading of fruit.
Macroclimate can be classified according to : (2)
- Temperature
- continentality
What are wine styles for cool continental climates and give examples?
- intensely-flavoured, late-harvested white wines with high potential alcohols which may be vinified as sweet wines (vendage tardive in Alsace) of dry (Smaragd wines in Austria’s Wachau)
What is phosphorus?
- P
- macronutrient
- key element in Energy fixation encourages root growth and ripening.
What does the slope or incline of a vineyard influence?
- sunlight interception
- air movement
- soil properties
- cost of working the land
What is Shale
Originally composed of clay, quite soft.
Soil texture is influenced by
- Organic matter
- Earthworms
- Wetting and drying
- Freeing and thawing
- Plant roots
- Cultivation
- Drainage
- Compaction
How is heat summation calculated (Amerine and Winkler)
Measuring the mean temperature for the month, subtracting 10 C and multiplying by number of days in month. Monthly sum are totaled for each of seven months of growing season.
Continental climate is charachterised by :
(temperpature, rainfall, )
- wide anual range of temperature (hot summers, cold winters)
- drier than maritime climate
*
What is the advantage of the drier climate in continental regions over maritime regions?
Is reduces the risk of rot at the harvest time and makes later harvesting less of a risk.
Why can bodies of water near a vineyard be negative in a cooler climate?
- it increases the humidity of a site, which increases the risk of fungal disease, in particular downy mildew.
What is the most commonly used climate indice?
Amerine and Winkler’s heat summation system (1944)
What does soil structure affect?
- the availability of water and air to plants
- the ability of fine feeding roots to penetrate the soil and exploit rhe essential plant nutrient supply
EU zone CIII : enrichment may not rise the total alcohol to more than?
13,5 %
What is the advantage of regions in a high lattitude?
They have a greater capacity to photosynthesise due to increased daylenght in the summer.
What are the major soil types associated with viticulture :
- limestone
- chalk
- slate
- granite
- volcanic rock
Why is altitude beneficial for hot climates?
- Vineyards can be planted at higher elevations in areas otherwise too hot for wine production
- it increases the cooling effect of wind exposure
A soil’s relative proportions of particle sizes affect
- Water holding capacity/availability
- Soil warmth
- Availability of nutrients
Name micronutrients in soil
Boron, Magnase, Copper, Iron, Molybdenum, Zinc, Cobalt, Chlorine, Silicon.
EU zone A : What is the amount of natural alcohol?
8 %
What is magnesium?
- Mg
- macronutrient
- Essential component of chlorophyll
- regulates internal acidity and sugar metabolism.
- Encourages ripening.
PH for alkaline soil
pH from 7.1 - 8.5
In hotter regions, a vine needs ______________ mm/year precipitation.
750