60 Port anD the Douro
Section 5: From the Saião to Barca d’Alva on the Spanish border, most of the Douro
Superior) including the River Sabor and areas away from the Douro around Freixo de
Espada and Vila Nova de Foz Côa: plus 140 to plus 460 points (14 sub-sectors).Altitude: On the basis that altitude has a marked effect on climate, scores vary between
240 positive points for vineyards situated up to 150 metres above sea level to 900 minus
points for those above 650 metres. Subdivided by locality (above), this effectively rules
out Port production from vineyards on the highest and therefore coolest margins of
the demarcated region.
Productivity (yield): Based on the principle that more productive vineyards produce
poorer wines, a maximum score of 120 points has traditionally been awarded to
vineyards producing 600 litres per thousand vines to a minimum of minus 900
points above 1,800 litres per thousand vines. However, in the light of the increasing
mechanisation of Douro vineyards and consequent lower planting densities (see the
section on planting below), the regulation now asserts a regional maximum of 55
hectolitres per hectare. Up to this limit all vineyards receive 120 points.
Soil type: A maximum of 100 points is awarded to schistous soils, minus 100 for soils
described as ‘transitional’, minus 250 for granite and minus 400 for alluvium. The
latter are virtually non-existent since the valley floor was flooded in the 1970s. The
only alluvial soils are to be found alongside the River Vilariça in the Douro Superior.
Vine training: Given that vines trained closer to ground level yield riper fruit, vines
grown up to a height of 0.8 metres are awarded 100 points (although an exception
is made nowadays for widely spaced vines). Vines growing on pergolas (a.k.a. Vinho
Verde) are completely excluded from Port production.
Grape varieties: These are covered in much more detail below, but the numerous varieties
planted in the Douro were originally classified by Moreira da Fonseca into five groups
ranging from 150 points for grapes described as ‘very good’, 75 points (‘good’), 0
points (‘regular’), minus 150 points (‘mediocre’) and minus 300 points (‘bad’). The
system has subsequently been subdivided into varieties that are either ‘recommended’
or simply ‘authorised’. Grapes that are recommended and considered ‘very good’ are
awarded 150 points whereas varieties that are authorised yet classified as ‘bad’ score
minus 150 points. The full list of recommended and authorised grapes may be found
in Appendix III.
Angle of inclination (slope): Bacchus amat colles (‘Vines love hills’) wrote Virgil, and it
is certainly true that the best vineyards are usually to be found on well-drained slopes.
One point is awarded to vines grown on a flat site with an inclination of up to 2 per
cent; up to 101 points for slopes in excess of 70 per cent.