How Many Grapes Are in Your Bottle of Wine?
By John and Jennifer VerPlanck
Here is a trivia question for you: how many grapes does it take to make a single bottle of wine? The answer? It depends on the winemaker.
Many years ago, a winemaker in Germany’s Mosel region instructed his workers to clip nearly half of the developing grape bunches and drop them on the ground. The local vineyard workers were appalled, having worked diligently to nurture the grapes up to that point; most of them quit on the spot.
So why propose such Draconian pruning? To decrease the yield. That sounds counter -productive doesn’t it? Why decrease the yield? Because he discovered that it forces the vines to produce better juice in fewer clusters for better wine.
Nearly every great wine estate limits their vine and grape growth. Smaller grape yield and judicious pruning are part of the viticulturist’s plan for less stress on the vines and better quality grapes. Typical harvests will range from two to five tons of grapes per acre, depending on the type of grape, age of the vines, weather, soil quality, trellising systems and planting density of the vineyard. Winemakers use a rough estimate average of 1 ton of grapes producing about 2 barrels of wine, with each barrel holding 60 gallons.
High production wineries often have the sole goal of output, so they may opt to push for fourteen tons per acre or more. One company in Australia has squeezed out twenty tons per acre. Adding sugar also will add to the overall volume to the wine, usually by about 5%.
The tonnage weight will vary due to the time when the harvest occurs, with early harvest berries full with juice and late harvest berries may be lighter with dehydration. Some farming practices that maximize flavor over tonnage yield include dry farming techniques which use no irrigation and result in more concentrated flavor in the berries, making for bold, powerful wines. In some regions this is mandatory by law as a means to protect the traditional style and quality of wine in a region.
The type of fine wine grape varies in size, too, with most being quite smaller than your average table grape. There are more than 5000 different wine grape varieties in the world. Averages of 70 to 100 berries per cluster but the size of the grapes vary widely. Some Riesling grapes average just 20 berries per cluster, Syrah, 40 berries to a cluster. Cab Franc and Cabernet Sauvignon grapes are quite small, weighing only one or two grams.
It’s estimated that a high quality dry wine averages about 2 ½ pounds or 600 to 800 grapes per single 750 milliliter bottle of wine. Free run juice or gentle pressing of the grapes takes more time and will yield less volume than high extraction methods which transfer harsh, extremely bitter crushed seed and stem characteristics to the juice.
So, how many grapes in your glass? If you fill your glass about a third full, about 120 to 180.
John VerPlanck and Jennifer Laskey VerPlanck