Tag Archives: schist

Graham’s Roots in the Schist at Quinta dos Malvedos

If you had to choose the single most important thing about the Douro, it would be the Schist. The region’s soil is predominantly made up of this rock: in fact, it can hardly be called ‘soil’ at all. This aspect of the Douro terroir means the vines develop great resilience, producing very low yields of grapes with the necessary intensity to make Port.

Schist is the result of the build up of sediment over milleniums, which under immense geological pressure forms layers of rock. This layering, or foliation, is the vital component for our vines. The roots of the vines are strong enough to work their way through the shattered sheets of rock in their quest for water. They therefore develop root systems that reach many metres underground.

The schist at Malvedos also has a high component of quartz in it. It is this that makes the rock glisten and sparkle in the sun. This is important: a natural thermostat amongst the vines. The dark rocks absorbs the sun’s heat, reflecting it back onto the grapes at night, creating a more constant temperature and thus ensuring a more even maturation of the grapes. But at the same time, the quartz in the schist reflects some of the sun’s rays; the result is that the earth around the vines never becomes too hot.

Schist is strong enough to build houses out of (and we do build our houses out of it in the Douro), while at the same time being soft enough for the vines push their way through. These are just some of the natural wonders of the schist at Malvedos.