Douro Harvest – How Port wine is made

Douro Harvest – How Port wine is made

The end of summer marks the beginning of one of the most important seasons in the Douro – the harvests! Discover the process that gives rise to the delicious Port Wine.

In September, one of the most important seasons in the Douro begins – the harvest!

During the day, men and women work from sunrise to sunset in the grape harvest, a manual and labor intensive process, but fundamental for the quality of the wine. At night, the voices rise up humming to the sound of the accordion while holding each other, tread the grapes until all the berries are crushed. Although the atmosphere is festive, the work is hard at this time that is the culmination of a year’s work for grape growers.

Discover the Douro harvest process, which gives rise to the delicious Port Wine.

Grape picking (harvest)

Colheita ou apanha da uva nas Vindimas do Douro - Rota do Douro
Fonte: Croft Port

“August matures. September harvest.” As this Portuguese proverb indicates, September is the month of harvesting the grapes which then reached the parameters of sugars and acid required for the production of wine. And as tradition dictates, harvesting is done manually starting with the first rays of sunlight.

One by one, the grape bunches are carefully selected and cut to be placed in boxes with a capacity of about 20 kg. It is precisely to allow a careful selection, ensuring the quality of the grapes harvested, the manual harvesting is still used in most of the Douro estates.

When the baskets are full, the workers transport them to a truck that will later take the grapes to a room where they will be checked manually, and the damaged grapes, leaves and other elements that should not be included in the wine production are discarded.

Treading the grapes

Pisa da uva nas vindimas no Douro - Rota do Douro
Fonte: Diário de bordo Luize Minotto @diariodebordolm

On the first night of the Douro harvest, the so-called “cut of the grape” takes place – the workers enter the mills and embrace in rows, step on the grapes, marching rhythmically back and forth. Despite the cheerful atmosphere, in which popular songs are sung, the work is hard and meticulous – all the grapes have to be crushed in order to separate the pulp from the film, which slides under the feet, making it harder.

As fermentation begins, the temperature of the must begins to heat up and the air is impregnated with the smell of crushed grapes. On average, the fermentation of Port wine lasts 3 days, thus maintaining a large percentage of its natural sugar.

On the second day, after the “grape cut”, a smaller group of workers goes back to the mills, this time to circulate freely in order to ensure that the grape skins – responsible for the color and tannins of the wine – are kept submerged, under the wort surface.

On the third day the workers no longer enter the mills because with the advanced state of fermentation, there is a great release of CO2. Using wooden utensils, which they call “monkeys”, to continue mixing the films with the liquid. When about half the natural sugar of the grape juice turns into alcohol, the tread stops and the skins accumulate on the surface, starting the fortification process.


Fortificação do vinho do porto, vindimas no douro - Rota do Douro
Fonte: Sogrape Vinhos

Fortification begins with the wine being taken from the mill and transferred to a vat. As the fermenting wine is transferred to the vat, a colorless, neutral wine spirit with an alcohol content of 77% is added. The addition of brandy increases the strength of the wine, making it impossible for the yeasts responsible for fermentation to survive. Since fermentation is stopped before all the sugar in the juice turns into alcohol, some of the grape’s natural sweetness is preserved in the final wine.

After this process, the wine is left to remain in the cellar in the Douro until the spring of the following year.

Maturation or aging

Maturação do Vinho do Porto - Vindimas no Douro - Rota do Douro

In March it is time to transport the new wines from the Douro region to the cellars in Vila Nova de Gaia, for the stage of aging. This transport was formerly done by the Douro River in traditional rabelo boats. But first each wine is evaluated in a tasting, deciding which style of Port wine will be destined – Aged Tawny, LBV, Vintage … Depending on the style determined, the wine is stored in large casks or small oak casks, where it will remain until the spring of the following year.

Thus begins the aging or maturation process. This process allows the wine and its flavors to develop and mature, and can be done in different ways and for different periods of time (at least 2 years), resulting in a wide range of Port wine styles we all know.

If you were fascinated with the Douro harvest process, know that there are several farms that offer visitors the possibility to participate in the harvest, picking and treading the grapes and also participate in Port wine tasting. One of them is the Enoteca Quinta da Avessada, located in the wine-growing plateau of Favaios, which constitutes an interactive museum alluding to the history and culture of the vine and wine in the Alto Douro region.
Come to know more about the Douro Wine Region and taste the delicious nectar produced on its slopes on board one of our cruises!