Deep Freeze in the Douro

What a difference a mountain makes.

At the port lodges, the guides recite facts about the Douro’s unique climate: how the mountains act as a buffer between Porto on the sea and the vineyards 65 miles inland. Serra do Marão (above) and Serra de Alvão are two hulking mountains that shelter the vines from the harsh Atlantic weather during Portugal’s brittle winter. In concert with the schist soil, which, brazier-like, absorbs the sun’s warmth during the day and releases it at night, these mountains keep the vines nice and cozy during the harsh winter months. And that keeps the grapes’ sugar levels nice and high for the Port wine.

When we left Porto at midday, the weather was sunny and crisp. By the time we crested Serra do Marão, we’d entered a winter wonderland. Yesterday’s rain in Porto was wet-packed snow here, and the dividing line between weather zones was as clearly demarcated as the earth-and-snow pinstripes that decorated the terraced vineyards.

Rounding the top of the mountain, we hit a wall of cloud that rose like smoke from the valley, bringing traffic to a grinding halt (above). It was a puffy gate to the Other Side: the warmer environment of the river valley. We slowly drove into the cloud bank and said goodbye to sunlight. For the rest of the day, a heavy sky pressed overhead as we zigzagged east along the banks of the Douro.

Normally, this dividing line is not so visible. But Portugal – and Europe – is caught in an extreme deep freeze, following weeks of rain and flooding.

Despite all the locks and dams installed on the Douro after the last great flood of 1989, the threat of flooding in Porto is still taken quite seriously. On New Year’s Eve in Vila Nova de Gaia, our Sandeman’s guide and her colleagues labored the night away, moving the library of precious old vintages to upper floors and tying down oak casks so they wouldn’t float away.

In Piedmont, the threat of fall hailstorms is a constant reminder how winemakers are farmers first and foremost; they can lose a year’s work in 10 minutes of hail. In the Douro, there’s also the river to contend with. In Port’s early days, it claimed lives as the flat-bottomed boats carrying wine casks shot the rapids from Pinhao to Porto. Clearly, the river’s caprices haven’t yet been fully tamed.