Vineyards are found in what three districts in the Duoro Valley?
Baixo Corgo, Cima Corgo, Duoro Superior
Baixo Corgo
Westernmost zone. Wettest port production zone. Coolest average temps. Grapes here mainly for inexpensive ruby and tawny ports.
Cima Corgo
Further upstream from Baixo. Summertime average tmp few degrees higher and rainfall is approx 200mm less. Grapes here higher quality, used in Vintage and LBV
Douro Superior
Easternmost zone, least cultivated region, hottest ad driest of Duoro
Describe soils in Duoro Valley
Soils are granite and schist. stony, shallow, free-draining. Poor in nutrients (limiting vigor).
Describe importance of Schist.
- Crumbles into layers easily
- splits into vertical layers, helping vine roots to dig deep into bedrock to find water (very little irrigation)
Methuen Treaty
1703 - ensured Portuguese wines received lower rates of duty in England than those of any other country.
What happened to Port in 1756?
Port vineyards officially demarcated and production regulations were drawn up by Marques de Pombal.
Pombal also created Real Companhia Velha.
- all ports had to be bought through this.
- there were fixed prices.
- it was given exclusive right to supply spirit for fortification.
- this was unpopular, but worked and port prices began to rise again.
What are the 3 types of vineyard layouts in the Douro?
Socalcos
Patamares
Vinha ao Alto
Socalcos
-Narrow terraces, supported by walls of dry rock.
-traditional method
-approx 6000 vines per hectare
-typically not suitable for mechanisation
UNESCO
Patamares
2 types: Large (2 rows of vines) and narrow (1 row)
- uneven ripeness can be issues with the large patamares
- terraces supported by a steep earth ramp.
- small tractors can run up and down slopes
- Positive: cheaper to implement/maintain than socalcos
- Negative: Erosion and growth of weeds can be an issue
Vinha ao Alto
- Vines plated in vertical rows
- least expensive + easiest to maintain
- negative: water run-off and erosion can be issue.
- use of this vineyard management is relatively limited.
Viticulture hazard in Duoro
- Late spring frosts (in highest altitude vineyards)
- Cool, wet weather from the west during early summer (disrupts flowers + fruitset)
- Downy mildew and botrytis (particularly in wet Baixo Corgo)
How are viticulture hazards managed?
- Canopy management
- Spraying with fungicides
- Fertilizers may be used to improve poor nutrient status of soil
- Herbicides to control weed that grow on slopes of patamares (these compete with vines for water and nutrients)
- cover crops grown on vinha ao alto to prevent erosion
Port: 5 main grape varieties
Touriga Franca Tinta Roriz Tinta Barroca Touriga Nacional Tinto Cao
*note over 100 varieties permitted and many vineyards planted with a field blend
What happened in Portugal in 1986?
Portugal entered the EU and producers were permitted to source and buy their own aguardente.
Touriga Nacional
• Considered the best of all Port grapes
• Low yields of small berries give wine high
in color and tannin, and intensely aromatic
• Produces deep, black wine with massive
extract and aromatics
Touriga Franca
Lighter, softer and rounder than Touriga Nacional, but gives very perfumed wines and tolerates heat and drought (most grown)
Tinta Roriz (Tempranillo)
- Early ripening, best in cool sites (susceptible otherwise to water stress), can produce high yeilds
- Contributes body, deep color”
Tinta Barroca
- Early ripening, best in coolest sites (otherwise prone to heat damage and grape shrivelling), high yield
- Contributes earthy aromas
- Can lack acidity (unless planted in cool sites) and color tends to fade more quickly”
Tinta Cão
- Late ripening, tolerant of heat, low yielding, thick skin, resistant to fungal disease
- Contributes concentrated wines, high acidity, ageing potential”
Best white grapes for Port.
Muscatel, Goveio, Malvasia Fina, and Viosinho
Instituto dos Vinhos do Porto e do Duoro (IVDP)
An interprofessional body created to supervise both Port and Duoro wine producers after the Casa do Douro went bankrupt from a bad investment in Royal Oporto.
How is the Douro demarcated?
The boundaries mostly follow the outline of the schist (it’s so important to the viability of grape growing in the region)
