Category Archives: Biodiversity

Miles on Barroca and Evolution

The Barroca we have been picking these last few days looks its usual self, just a hint of softness where the berries have started to lose moisture through evaporation. It is their thin skins that allow this to happen, and it concentrates the sugars in the fruit giving this variety its famous sweetness. This year we have even spotted some with more than 17º Bé.

 It always amazes me to see what our vines are capable of producing under extremely difficult conditions. Often the harder the year, the better the wines we produce. A friend of mine who is a viticultural research scientist told me about a conversation he had with some Australian colleagues. They were chatting about interesting things, such as the relationship between leaf water potential and photosynthesis. The Australians were flabbergasted to hear that compared with the Northern European varieties they had been investigating, the Touriga Nacional was literally off the scale. Long after the other grapes had given up totally on the idea of photosynthesis, the Nacional was quietly working away ripening the grapes at unbelievable levels of water stress.   – Miles Edlmann

We seem to forget that these varieties have evolved over thousands of years to be perfectly adapted to Douro conditions – i.e. extremely dry soils with very low organic matter, and a large percentage of the volume taken up by stones.