You can feel it in the air…the excitement and anticipation of harvest! The vines are lush and green, the fruit is nearly ripe, and preparations are busily taking place in the vineyard, the press room, and all around the Wollersheim grounds.

Winemaker Philippe and crew are just about ready to begin making the 2017 vintage. “Things are looking really nice,” he says. “We are so looking forward to a great vintage. It’s been a long time since we’ve seen a good year like this, where we have quality and quantity.”

Red Grapes

While conditions are carefully being assessed daily, Philippe expects harvest to begin near the end of Labor Day week, continuing into the third week of September. “We’re not rushing into it,” he explains. “With the mechanical harvester, we truly can wait until the grapes are at perfection. We can pick a field at a time, a block at a time.”

But how do they know when the time is right and the grapes are ready to be picked? There are four key factors:

Sweetness: To measure the sweetness of the grapes, Celine uses a refractometer, which gives the percentage of sugar in units called Brix. During fermentation, theses naturally-occurring sugars will become alcohol, and the amount left behind when fermentation is stopped will determine how sweet the wine will be. When it comes to wine grapes before harvest, Philippe says, “The sweeter, the better, because that’s when you have the full flavor.”


Acid/pH: It’s important to wait for the grapes to ripen to the right sweetness to produce a flavorful wine. But, Philippe says, “you cannot wait so long that all the acid is gone. A balanced wine needs enough acidity.” Acidity gives wine lightness and brightness, and balances sweetness. To keep an eye on acidity before harvest, Celine measures pH, or concentration of acid, every few days.

Measuring pH

Weather: What kind of weather do Philippe and his crew hope for before and during harvest? The key is sunlight, along with warm (but not too-hot) temperatures. When the sun is shining, the grapes are able to make sugar…so “sun, sun, sun is critical right now.” What kind of weather can be tricky for harvest? Rain. Too much rain can water down the natural sugars in the grapes and affect the flavor of the wine.


Taste: This part of deciding whether a crop is ready for harvest cannot just be measured with instruments or expressed in numbers. When sampling grapes in the vineyard, Philippe looks for “nice, soft, ripe flavors” and “a nice balance of acid and sugar.” Although machines can give accurate readings on sweetness and pH, no machine can match the trained palate of a seasoned winemaker when it comes to taste.

White Grapes

Once that fine balance of flavor, color, sweetness and acidity is reached, it’s time to start harvest! As Philippe says, “the fun is about to begin again…it’s winemaking season!”