FNH 330 L3 Viticulture: terroir and geographical factors

What is viticulture, and what is it called when the objective is wine production?

Viticulture: the science, production, and study of grapes; deals with events in the vineyard

• When the objective is wine: called wine-growing or viniculture

What is the main wine grape species, what does its name mean, and what are examples of white and red cultivars?

Species: Vitis vinifera — Latin: vin = wine, fera = bearing

• White cultivars: Pinot Blanc, Chardonnay, Sauvignon Blanc

• Red cultivars: Pinot Noir, Merlot, Cabernet Sauvignon

What is terroir, and what are its two interacting components?

What are examples of terroir differences?

The direct and interacting effects of (1) viticulture and (2) the physical and biological environment, that together result in the unique characteristics of a wine from a given site

Physical/biological environment includes:

- Soil (texture & structure)

- Climate

- Topography

- Slope and aspect

- Biodiversity

What does the Meursault vs. Montrachet example illustrate about terroir?

Two adjacent Burgundy vineyards appear identical (same vines, same appearance), yet wines differ dramatically in value (~$81 vs. ~$881/bottle)

• Attributed entirely to soil differences

• Key point: terroir can produce major quality differences with no visible cause in the vineyard

What are the two roles soil plays in vine growth?

• Anchors the vine; supplies nutrients and water essential for growth

• Mediates the vine's growth rate and balance between reproductive (fruit) and vegetative growth

Compare the three soil particle types by drainage and water/nutrient holding capacity. Include Canadian examples.

Define WHC and NHC.

• Sand: coarse; rapid drainage; low WHC & NHC

— e.g. south Okanagan Valley, BC

• Clay: fine; very slow drainage; high WHC & NHC

— e.g. Niagara Peninsula, ON

• Silt: moderately fine; moderate WHC & NHC; moderately slow drainage

• Loam = mix of silt, sand, clay

— e.g. Fraser Valley, BC

WHC = Water Holding Capacity

NHC = Nutrient Holding Capacity

What do organic matter and limestone each contribute to vineyard soil?

• Organic matter (compost/manure): improves WHC and NHC; moderately improves drainage; adds slow-release nutrients

• Limestone/calcium carbonate: moderate WHC; regulates acidity (pH); considered valuable in vineyard soils

(e.g. Terra Rossa over limestone, Coonawara, Australia)

What is the ideal soil management approach, and what is the fallback when soil cannot be modified?

• Soil may be managed to promote desirable vine growth, OR vines/wines simply reflect the existing soil type

• If soil cannot be practically modified: critical to plant the right grape variety and/or rootstock

• Note: vines can be grown on many soil types — there is no single ideal soil

Which of the following is NOT a role soil plays in growing wine grapes?

A) Physically anchors the vine

B) Contributes flavours like minerality directly

C) Provides a growing medium

D) Moderates vegetative/fruit growth balance

E) Influences growth rate

Answer: B — soil does NOT directly transfer flavour compounds (e.g. minerality) into wine

• Soil influences vine physiology and growth, but flavour is not absorbed directly from soil into grapes

How do climate, weather, and vintage relate to each other?

• Climate: long-term average regional weather (expected, known)

• Weather: actual growing season conditions (temperature, sunshine, cloud, rainfall) for a single year — highly influences yield and quality for that vintage

• Vintage: the year grapes were harvested (S. hemisphere) or grown and harvested (N. hemisphere)

• Exception: Icewine — grapes may be harvested in a different calendar year than when they grew

What are the six characteristics of an ideal climate for growing wine grapes?

• Sufficient and timely rainfall (or irrigation), heat, and sunlight

• Light winds (to dry vineyards after rainfall/irrigation in high-humidity areas)

• Low to no frost

• Low to no hail

• No drought

• No late-season rainfall

In what latitude range does Vitis vinifera grow best?

• Between the 30th and 50th parallels of latitude, north and south (temperate zones)

• Does not grow well outside these zones

What are the four recognized climates for growing wine grapes?

• Mediterranean, Continental, Maritime, Cool

Describe the Mediterranean climate: conditions, pros, cons, varieties, and example region.

• Conditions: mild/sometimes wet winters; dry, hot summers

— e.g. South Rhone, France

• Pros: ripens long-season reds to high quality; less disease; consistent vintages; little/no cold injury

• Cons: water limitations; sun scald on berries; loss of acid and aroma compounds in high heat

• Varieties: Marsanne, Roussanne, Grenache, Cabernet Sauvignon, Syrah

Describe the Continental climate: conditions, pros, cons, varieties, and example region.

• Conditions: cold winters, warm-hot summers; large seasonal temperature range

— e.g. Burgundy, France

• Pros: many variable mesoclimates — good to high quality for certain varieties

• Cons: winter cold injury and frost; vintages quite variable (excessively wet or dry)

• Varieties: Chardonnay, Merlot, Riesling, Cabernet Franc

Describe the Maritime climate: conditions, pros, cons, varieties, and example region.

• Conditions: adjacent to a large body of water; cool winters, no long-term dry season, warm-hot summers

— e.g. Bordeaux, France

• Pros: some varieties excel when sunshine/heat units are sufficient; little cold injury

• Cons: often too wet; rain during harvest season; disease issues; limits variety selection

• Varieties

— Cooler areas: Bacchus, Chardonnay, Pinot Noir

— Warmer areas: Cabernet Sauvignon, Merlot

Describe the Cool climate: conditions, pros, cons, and varieties. Give an example region.

• Conditions: short, cool growing season (avg 14-16°C); cold winters; summers variable but can be cool to warm

— e.g. Mosel or Rheingau, Germany

• Pros: good varietal character in white wines and Pinot Noir

• Cons: short summers (fewer frost-free days); vintages quite variable; heat accumulation at lower limit for viticulture; frost and winter cold injury are concerns

• Varieties: Chardonnay, Riesling, Pinot Noir, Müller-Thurgau

Which climate is most prone to rainfall during the harvest season, and why?

• Maritime climate — no long-term dry season means rain can fall at any point, including at harvest

• This is also why variety selection is limited in maritime regions

What are the four categories of geographical factors (beyond soil and climate) that affect vineyard site suitability?

• Topography (mountains, slope and aspect)

• Water availability

• Altitude

• Proximity to bodies of water

What is a rainshadow, and what effect does it have on viticulture? Give examples.

Rainshadow: mountains block rain-producing weather systems, casting a zone of dryness behind them

• Creates drier conditions than would otherwise exist — beneficial for disease control and consistent ripening

• Examples: Alsace (France), Marlborough (NZ), Pfalz (Germany), Columbia Valley (WA), Okanagan Valley (BC)

How does access to irrigation water affect viticulture in dry climates? Give examples.

• Water access allows land otherwise too dry for grapes to be farmed

• California's south Central Valley: water sourced from Sierra Mountains

• Chile's Central Valley: water sourced from Andes Mountains

How does high altitude benefit viticulture in warmer climates? Give an example.

• Altitude provides cooler days, cooler nights, and breezes

• Creates conditions suitable for white grape varieties in regions that would otherwise be too hot for quality wine

• Example: Eden Valley, South Australia

Why are south-facing slopes particularly valuable in cool-climate regions of the northern hemisphere? Give an example.

• South-facing slopes enhance the vineyard's orientation toward the sun (which tracks across the southern sky in the N. hemisphere)

• Improves the warming pattern over the growing season

• Allows wine-growing to exceed quality expectations for such a northerly, cool climate

• Example: Rheingau, Germany

What is "morning fog followed by drying hot sun," how does it affect the grapes, and where does it occur?

• Morning mist from rivers promotes Botrytis cinerea ("noble rot") — the fungus compromises berry skins

• Later, hot drying sun evaporates water, concentrating sugars, acids, and aromas/flavours in the berry

• Example: Sauternes, France (used to produce sweet botrytized wines)

What is "aspect" and why do slope and aspect matter in viticulture?

• Aspect: the compass direction a slope faces (N, S, E, W)

• Slope and aspect influence microclimate by determining how much solar radiation a vineyard intercepts during the growing season

• Can make or break site suitability — especially in marginal climates

What is the core principle for reasoning about slope and aspect in the northern hemisphere?

What happens at 0 degree slope?

• The sun tracks across the southern sky in the northern hemisphere

• Slope amplifies whatever the aspect is already doing relative to the sun:

- South-facing (toward sun): more slope = MORE radiation intercepted

- North-facing (away from sun): more slope = LESS radiation intercepted

- East/west-facing (sideways to sun): moderate, gradual decline as slope increases

• Rule: aspect toward the sun + steeper slope = more heat; aspect away from sun + steeper slope = less heat

At 0° slope (flat ground): all aspects receive the same radiation — differences only emerge as slope increases

How does the slope/aspect relationship change in the southern hemisphere?

• The sun tracks across the northern sky in the southern hemisphere

• Direction reverses: north-facing = toward sun (gains radiation with slope); south-facing = away from sun (loses radiation with slope)

• The logic is identical — just swap north and south

What is the Winkler Index, what does it measure, and what is it used for?

• A climate classification system for viticultural regions

• Uses Growing Degree Days (GDD) — a measure of heat accumulation over the growing season

• Divides regions into Regions Ia through V based on total GDD

• Used to determine which grape varieties are suitable for a given region

How are Growing Degree Days (GDD) calculated?

Step 1: Calculate average daily temperature = (max T + min T) / 2

Step 2: Subtract 10°C from each day's average

Step 3: Sum all positive daily values across the growing season

Result = total GDD for that season (10°C is the base threshold — below this, grapevines do not meaningfully grow)

sum each (daily avg temp - 10°C)

ADD INDEX TO CHEAT SHEET

Why do GDD values vary between vintages, and what does this mean for wine quality?

• Weather varies year to year — some growing seasons are warmer or cooler, longer or shorter

• GDD variation among vintages is typical and results in quality differences between years

• This is a key reason why vintage year matters on a wine label

What is the EU wine-growing zone classification system, how many zones does it define, and what are they used for?

• The EU defines 6 climatic viticulture zones for European wine-growing regions, based on temperature (last updated 2008)

• Zones:

A (Coolest)

B (Cool/warm)

CI (Warm/hot)

CII (Hot)

CIIIa (Hot longer)

CIIIb (Hot longest)

• Used to determine: permissible viticulture practices (e.g. irrigation) and vinification practices (e.g. addition of sugar or acids)

Match these major French wine regions to their EU climate zone: Champagne, Alsace/Germany/Loire Valley, Burgundy, Bordeaux, Rhone.

• Zone A (Coolest): Champagne

• Zone B (Cool/warm): Alsace, Germany, Loire Valley

• Zone CI (Warm/hot): Burgundy

• Zone CII (Hot): Bordeaux

• Zone CIIIa/b (Hotter): Rhone and southern regions