This small but remarkable property has a long association with Fonseca and has been contributing wines to its Vintage Port blend for the last hundred years.
Entirely converted to organic viticulture, it occupies an open hillside facing westwards down the Pinhão River about a kilometre north of Fonseca's Quinta do Cruzeiro. The estate was included in the first classification of Douro vineyards in 1757.
The wines of Santo António are finely constituted and aromatic, adding vibrancy and complexity to the Vintage Port blend.
Conversion of the property to organic viticulture began in 2007 and the property achieved full organic certification in 2010. Santo António is a showcase for the sustainable viticulture model developed by technical director David Guimaraens and head of viticulture António Magalhães. This builds on the experience in vineyard landscaping and organic viticulture acquired at Fonseca's other two properties, Quinta do Cruzeiro and Quinta do Panascal.
The Douro Valley is one of the most impressive of the world's wine producing regions. The oldest vineyards cling to the steep hillsides on tiers of narrow walled terraces which form a spectacular man made landscape, classified as World Heritage. Today it is no longer viable to construct these traditional terraces with their dry stone walls built laboriously by hand over the centuries. Where the gradient is less than 30% they are replaced by vertical rows of vines running perpendicularly up the hillsides, a technique known as vinha ao alto. However about two thirds of the vineyards of the Douro are planted on steeper gradients where vertical planting is difficult or impossible.
Here the vines are planted on broad platforms, following the contours of the hillsides, known as patamares. These have no walls but are separated by tall earth banks. If not sensitively constructed these modern terraces can have a negative effect on the environment, cutting across natural water courses, causing erosion of the shallow topsoil and creating a barren environment hostile to wildlife. The need to keep the tall earth banks clear of weeds, which compete with the vine for water in this arid region, often involves the use of chemical herbicides.
The model developed by António Magalhães and David Guimaraens is a blueprint for constructing and managing modern terraced vineyards in a way that is economically and environmentally sustainable. Winner of the BES Biodiversity Prize, Portugal's most prestigious conservation award, it incorporates a number of techniques and strategies which work together to create a balanced and diversified ecosystem, reduce or eliminate the use of harmful chemicals and assure the economically viable production of very high quality wines.
The model is based on the construction of narrow terraces each supporting a single row of vines. The terraces, are engineered using earth-moving equipment in which the operator is guided by an innovative laser orientation system which allows the terraces to be built with a gradient of exactly 3%. At this inclination, a balance is achieved between rainwater run-off and its penetration in the soil, avoiding the topsoil erosion which constitutes one of the main challenges in hillside viticulture.
The model also eliminates the use of chemicals to control unwanted vegetation. This is achieved by allowing unrestricted access to the earth banks, which are lower and more accessible than those used in conventional patamares, so that any natural plant growth can be cut back mechanically. The dry stubble on the banks helps stabilise them and provides a habitat for insects and other wildlife. Alongside the vines, control is achieved by sowing a temporary carpet of drought sensitive cover plants such as clover and lupin.
This remains between November and late spring while the vines are dormant, preventing invasive plants from taking hold. It then dies back naturally with the onset of summer and can be mown mechanically to form a natural carpet between the vines, reducing water loss and restoring natural organic matter to the soil. Other components of the model include the planting of olive trees and the conservation of patches of natural vegetation, ensuring the diversity of plant and animal life often depleted in areas of intensive viticulture.
Perhaps the most critical aspect of all is the correct selection of vine varieties and their distribution within the vineyard, ensuring that each variety is optimally located and able to thrive naturally, developing its own unassisted resistance to drought, disease and vineyard pests, while continuing to produce high quality and perfectly ripened grapes.
The model was originally devised for economic and environmental sustainability rather than organic production. However at Quinta de Santo António it has been taken a step further to full organic certification. Not all of the property has been re-landscaped, however. The quinta contains an area of very old traditional walled terraces which have been preserved but replanted so that they can be managed organically.
Organic certification includes the estate's many olive trees. Just over half are of the Galega (Negrucha) variety, the remainder being mainly Madural and Cordovil with a small proportion of Cobrançosa. The olives from these old trees are cold pressed to produce a wonderfully fragrant organic extra virgin olive oil. Smooth, delicate and aromatic with a subtle fruitiness, it is an international trophy winner and popular among devotees of specialist olive oils.