Wine
Harvest, what actually happens when the grapes come in
Between July and September the vineyard reaches its decisive week. How the picking date is chosen, and why harvest became a celebration.
· 3 min read
Of a vineyard's entire agricultural year, a handful of days determine the result. Harvest is the moment when eleven months of work come down to a decision about the calendar.
Why the day matters so much
As grapes ripen, two things happen simultaneously and in opposite directions: sugar rises and acidity falls.
The sugar will become alcohol during fermentation. Acidity is what gives wine freshness and structure, and what allows it to age.
Pick early and you get a light, green, possibly herbaceous wine. Pick late and you get a heavy, alcoholic, flat one. The correct point is a narrow window, and in warm climates it can last only a few days.
That is why, in the preceding weeks, someone walks the vineyard every single day.
How the decision is made
Three readings are combined:
The numbers. Sugar is measured with a refractometer and acidity analyzed in a lab. It provides an objective baseline, but it is not sufficient on its own.
Skin and seed ripeness. In reds this is decisive. Tannins from a green seed are bitter and astringent; from a ripe seed they are round. A grape can have perfect sugar and still-green tannins.
The palate. The grower walks and tastes fruit from different parts of the vineyard. It is the least scientific method and usually the deciding one.
On top of that comes the weather forecast. Rain before harvest swells the fruit and dilutes concentration, so an incoming front can move the picking date up by several days.
Why they pick before dawn
In warm climates much of the harvest happens at night or in the first hours of daylight.
The reason is simple: warm grapes begin oxidizing and fermenting spontaneously in transit. Arriving cold at the winery, the winemaker controls the process from the start. It is also far more pleasant to work without the sun overhead.
By hand or by machine
Hand harvesting allows cluster-by-cluster selection and discarding what is not good. It is more careful and more expensive.
Machine harvesting is fast and economical, and across large areas it is the only viable option.
For high-end wines, hands still win.
And afterward
The fruit reaches the winery and the part almost nobody sees begins. It is sorted on a table, destemmed, crushed. In reds, the must ferments with the skins, which contribute color and tannin; in whites it is pressed beforehand to leave them out.
Fermentation takes days or weeks. Then come aging and waiting, measured in months or years.
In other words: the harvest celebration marks the end of one stage and the beginning of a considerably longer, quieter one.
Why it became a celebration
Historically, harvest required many hands over few days. Entire families, neighbors, people arriving from other towns. Finishing the harvest meant the year was secured, and that was worth celebrating with food and drink.
Mechanization reduced the need for hands, but the custom stayed. Today harvest festivals are among the main draws of wine tourism, in Coahuila and across the wine-producing world.
At Amargos, with a vineyard since 1946, harvest still marks the high point of the year.