Tales from the Crush Pad #4: How Many Grapes Make a Bottle of Wine?

The first grapes of the 2022 vintage arrived at Gary Farrell Winery on August 12th which amounted to nearly seven tons of Pinot Noir from Starr Ridge Vineyard. Over the coming four weeks, grapes would continue to flow with deliveries nearly every day. The entire cellar staff was surprised by the early August harvest which we would soon find, would wrap up more quickly than most years. Following a Champagne toast by our head winemaker, Theresa, the team got busy processing 14 half-ton bins of grapes.

With this exciting start to the 2022 vintage, quite a lot of grapes are coming through this Crush Pad – 471 tons, to be exact. But how much wine will this make? And how many grapes does it actually take to make a bottle of wine?

The easy answer is about three pounds of grapes make a bottle of wine.

From there, things get more complicated. Every grape is different so it’s hard to give a firm number. There are more than 10,000 different types or varieties of wine grapes grown around the world. Each variety has different characteristics that determine how they grow, what weather conditions they thrive in, and how they taste. Some vines produce only a few clusters while others produce 40 to 50. Clusters can be large – like Cabernet Sauvignon – or small – like Pinot Noir. Some grape varieties are barely bigger than a green pea while others are as large as a plump cherry. And then there are the farming practices to consider. It is a common belief that the quality of the grape is better when there are fewer clusters on the vine. On the other hand, most grape farmers sell their fruit by the ton. The more tons a farmer produces, the more money they make for the season.

So, when it comes to figuring out how many grapes went into your bottle of wine, it’s complicated. While this may be an interesting albeit useless piece of trivia for most wine lovers, it is quite important for the winemaker to know. Each harvest year, or vintage, a winemaker must estimate how many grapes they will receive by weight. This information allows the winemaker to budget what they will be paying the growers and project how much wine they will make. Plus, they must know the volume of juice the grapes will yield, so they can be sure there is enough space in bins, tanks, and barrels for fermentation of the juice into wine.

The bottom line is, while making wine is artistic, there is still quite a bit of science – and math.

To estimate the amount of wine to come from a harvest or how many grapes go into a bottle of wine, we have to take the weight of grapes and convert that to a liquid volume. There’s no exact calculation to do this. But, using counts I have taken in the wineries, reports from farmers and winemakers, and published articles by both the University of California at Davis and Cornell University, we can come up with some averages to help give an idea.

Here are some of the averages I’ve discovered:

• 4 tons per acre
• 900 vines per acre
• 85 grapes per cluster
• 40 clusters per vine
• 1/4 pound per cluster
• 2,000 pounds in a ton
• 160 gallons from a ton
• 59 gallons in a barrel
• 2 gallons per bottle

In the vineyard, an acre has about 900 vines depending on the spacing of the rows. An acre yields an average of six tons of grapes. But I’ve found that most commonly, a quality vineyard whose grapes are used for premium-level wines will yield about four tons per acre. This is, of course, variable because of the variety of grapevines, the spacing of the vines in the vineyard, and the farming practices. Some vineyards produce 10 or 12 tons per acre, and some, like the renowned Opus One in Napa Valley, aim for only one ton per acre. We’ll use four tons for our calculations because we drink premium wines, right?!

There are between 70 and 100 grapes on a typical grape cluster. Let’s split the difference and say 85 grapes per cluster. A typical grape vine will produce about 40 grape clusters. An average cluster weighs anywhere from a quarter to a half of a pound. I like to use 1/4 for my calculations unless I’m specifically talking about a grape variety that produces large clusters. One vine can grow about 10 pounds worth of grapes. A ton is 2,000 pounds, so it takes about 8,000 clusters to make up one ton of picked grapes. This means it takes about 200 vines to grow those 8,000 clusters making up one ton of grapes.

Each ton gives us about 160 gallons of grape juice. A standard wine barrel holds 59 gallons so one ton of grapes usually gives the winemaker 2.7 barrels of wine. But there are considerations with these averages too. Grapes can be pressed gently or hard which determines the amount of juice that comes from the ton. And during the process of moving the juice from the press to a tank or barrel, some wine is lost. Have you ever heard of ‘the angel’s share?’ This is the term we use for the small amount of wine that naturally evaporates from a barrel during the aging of wine. So, to be on the safe side, I’d consider two and a half barrels of finished wine per ton of grapes.

At an average of 2.5 barrels of wine per ton and 4 tons per acre, an acre gives us 10 barrels of wine. A standard wine barrel holds 59 gallons, so we’re talking about 590 gallons of wine from one acre of vines. A single standard bottle is 750 millimeters, which equals 0.2 gallons. So, a barrel holds 24.5 cases of 12 bottles, totaling 2,950 bottles. Each bottle holds 4.5 glasses of 6-ounce pours.

So, by these numbers, each vine makes 2.6 bottles or nearly 12 glasses of wine.

Since a barrel gives us 24.6 cases of wine, which is 295 bottles, one ton of grapes equals 61 and a half cases, which is 738 bottles of wine. And one bottle requires about two and a half pounds of grapes to make up the 750 milliliters or 0.2 gallons. Filling a standard wine bottle takes about 10 clusters at 0.25 pounds each and ten clusters would be about 850 grapes in a bottle – give or take.

Wine websites will quote 400, 600, 800, or even 1,000 grapes go into a bottle. Again, this is very hard to determine! I feel 850 is a good number, even though some grape varieties and farming practices will come up with a lower or higher number. And from my personal experience of making a Texas Montepulciano in 2021, I can say this is a pretty accurate number.

Gary Farrell Winery will ultimately receive 471 tons of grapes in the 2022 vintage. That comes to about 75,360 gallons making up 376,800 bottles or 31,400 cases of wine.

In a previous article, I promised to share the wine books I’m catching up on during this journey. As these first grapes came into the winery, my job would be to sort the clusters. Two more ladies who worked alongside me who are part of a labor service in the area. Later I will touch on wine services in California which are not common in Texas. Anyway, while sorting the grapes, I started an audiobook by Laura Dave, a novel titled Eight Hundred Grapes. Unlike my educational reads, this is a love story set in Sebastopol on a family vineyard. It was accurate regarding the vineyard and wine details with family drama, love that comes and goes, and a bit of mystery. Overall, an easy listen that took just eight hours – a full day of sorting grapes. You can download the book here.

In future articles, I will share some details about the specific varieties we are processing and some differences in making wine in California versus Texas.

Cheers y’all!