Why port wine is still made by stomping grapes

• Foot treading, stomping grapes by foot to extract the juice, is at the heart of the making of authentic port wine.
• It is a very traditional and labor-intensive method, yet it is still the one producing the finest ports.
• We visited Quinta de Vargellas, a wine estate owner by Taylor's, one of the founding port houses.
• Although port wine bears the name of the seaport city of Porto, it is actually in the steep hillsides of the Douro Valley in northern Portugal that it has been made for centuries.
• The region was legally demarcated by the Portuguese government in 1756, meaning that authentic port can only be made here.

Following is a transcript of the video.

If you travel to the Douro Valley in nothern Portugal during the harvest season, it would be hard to miss the festive atmosphere and the music playing all night long in the the quintas, the wine estates in the valley.

That is because every year, after a day spent harvesting grapes, the pickers perform what is called "foot treading," where they stomp grapes by foot to extract the juice from the fruit. Foot treading lasts for hours, and it is done first in silence, and then is accompanied by music. It is a very traditional and labor-intensive method, yet it is still the one producing the finest ports. Why is that?

We visited Quinta de Vargellas, a wine estate owner by Taylor's, one of the founding port houses. It was established in 1692 and owns 500 hectares of vineyards in the Douro Valley. The quinta is one of the company's most prestigious estates and home to some of its finest ports.

Although port wine bears the name of the seaport city of Porto, it is actually in the steep hillsides of the Douro Valley in northern Portugal that it has been made for centuries. The region was legally demarcated by the Portuguese government in 1756, meaning that authentic port can only be made here.

"Port wine is a fortified wine," Taylor's Head Winemaker David Guimaraens told Insider. "And what differentiates port from a normal wine is that we will take the grapes, and if you were to make a red wine from these grapes, you would let all of your sugar be transformed into alcohol, and the final alcohol of the wine is the result of the initial sugar in the grape. In a port wine, we will take the same grapes, start fermenting, and when half of the sugar has been converted to alcohol, we will run off the juice. And we will add a neutral grape spirit, which will kill the yeast. So the sweetness in the glass of port is the natural sugar from the grape. And the wine alcohol, the spirit that we use, is there to raise your port to an alcohol level of 20%, where it is stable and has the ability to age."

Every September, a group of grape pickers from the villages of the Douro Valley is recruited to do the harvest. They are paid, fed, and get accommodation at the Quinta. The pickers start working at 8 a.m. in the vines, where they pick grapes by hand. At sunset, they move indoors to press the grapes by foot.

"One of the beauties of foot treading and using this very simple process is that your foot is doing an intense action of taking the color out of the skins, but at the same time it's very soft," said Guimaraens. "So you extract what's good, and you leave behind what is more aggressive. And that is so difficult to replicate in any mechanical means. And that's why we continue to use it."

EDITOR'S NOTE: This video was originally published in October 2019.