Understanding Wine Grape Clones

Have you ever heard someone describe their wine by saying, “this Chardonnay exhibits the classic elements of the Wente Clone,” or, “this Pinot Noir shows the intense berry fruit of the Pommard Clone”? We’ll tell you why.

As wine consumers are branching out and trying new varietals and regions, they too are looking to find out as much as they can about the wines they are being introduced to. Among many popular buzz words in the wine industry is “clones”; in fact, these days many wines are being described strictly by their grape clones.

What does all this seemingly “highbrow” terminology mean? In a way, referring to a wine grape’s clone offers an ability to distinguish different varieties of the same grape varietal from one another, much in the same way wines themselves are compared and contrasted with each other. And while this may be of use to some consumers, it’s more advantageous to the viticulturists and winemakers. So for this purpose, let’s take a step back and talk about grape vines and how they came to be, and how they have evolved over time.

How Grape Clones Are Created

First it is important to understand how grape vines are grown. Many varietals we know today (if not all) are actually grape clones or mutations, if you will, of two parent varietals. For example, one that happened more naturally is Cabernet Sauvignon. Although Cabernet Sauvignon is a widely popular grape, it is actually relatively new in the grand scheme of things, and was a product of the crossing of the Cabernet Franc and Sauvignon Blanc grape varietals, believed to have happened sometime during the 17th century in France. This type of plant reproduction is referred to as sexual propagation.

Though many wine grape varietals happened out in the vineyards in this “Mother Nature taking its course” kind of way, other varietals came to be through science. One example is the Pinotage grape varietal, which was a crossing of Pinot Noir and Cinsault by South African Viticulture Professor Abraham Izak Perold in the 1920’s. Perold was seeking to create a grape variety that was easier to grow than Pinot Noir, but still had the fruit characteristics of Pinot Noir and the heartiness of Cinsault.

Though one happened in the field one happened in a lab, both were the result of seeds growing together to create a new wine grape varietal. In these examples one can say that these two varietals have both a mother and a father, and continuing to grow vines from that pairing retains the characteristics of this particular variety to an extent, but we’ll get to that in a minute.

Breaking Down the Process

Now, it is very important to note that a specific grape varietal is a unique single event from those two parent grape varietals, and that going back and crossing another Cabernet Franc and Sauvignon Blanc will not result in the same identical new grape varietal.

For example, consider dog breeds. The same mother and father can have a litter of several different puppies, but usually each puppy will have its own distinct characteristics. One may have a longer nose, hair color may vary slightly and some will even have different shaped and sized ears. And this even happens when the mother and father are of the same breed.

Well this same sort of thing happens is the grape vine world. But with grape vines you can take a cutting and continue to grow that same varietal over and over again. As someone who enjoys gardening, I do this with my basil plants all the time; I take a cutting and root it in water before planting it and growing a whole new plant. This example is one type of vegetative propagation, with two other methods being grafting and layering. In layering, the vine is simply bent over from a neighboring vine and covered with dirt, and in time this segment will begin growing its own independent root system. However, cutting and layering can take time, so the grafting method is a popular choice. Grafting involves removing the top, or canopy, of the plants and replacing it with a cutting. While grafting will take time, it is a lot quicker than the other two methods and the vines are usually able to start producing fruit much quicker. For the most part, you will get pretty much identical characteristics in the new growths.

Varietal Mutations

Vines, like all plants, rely on the sun to grow, but they also are subjected to the sun’s radiation as well. Due to sun radiation exposure, vegetative propagated plants will often have spontaneous mutations of their genetic DNA, ranging from very slight differences (if even noticeable at all) to some more extreme changes. With very slight changes, some usually will go completely unnoticed, not exhibiting any or enough differences in desired characteristics of a plant. To the extreme, there may be a mutation that has completely undesirable qualities, and then the plant would most likely be removed.

But somewhere in between there could be plants that take on noticeable changes, including qualities that a grower may find favorable. Some of these qualities can be: larger or smaller berry size, yield size (how many grape clusters per vine), fruit color or aromas, fruit maturation rate, and even some that are resistant to disease. When a change is favorable the viticulturist may decide to further develop that new clone.

To be considered a clone, a plant must possess different characteristics from the original plant; at that point the new clone taking on its own name. Some have names designated by a region or winery, such as the aforementioned Pommard and Wente clones, others are a little more clinical with names like 667 or QM-1. Even the Dijon clone has some variances and is designated by additional numerals to distinguish one from another. But for today let’s not get too technical.

Why You Should Care About Grape Clones

Okay, so now you’re brought up to speed on more than you may have wanted to know about grape vines and varietals versus clones, but how does all this translate to what you are pouring into your glass? As new wineries are planting vines, or established vineyards are replanting, the viticulturist and winemaker may look to specific clones to achieve the end result that they are looking for in a wine. Some grape clones may be more fruit forward while others offer more structure. Some clones may have higher sugars or acidity, which can alter a wine’s alcohol content or create a more crisp and refreshing wine. Some may simply grow better in a specific region, in regards to climate or soil type. So when selecting grape clones, the winemaker or viticulturist has the ability to already steer their wines in a specific direction.

While there are some vineyards out there planted with single grape clones, there too are some vineyards planted with a variety that when blended will create a wine with all the characteristics that the producer desires. Some producers may take a great deal of pride by depicting the clone type on the label of a bottle; some even naming their wines for the specific clone. But in the end it’s about the desired result in flavor and other wine characteristics that the producer is looking to achieve. And who knows…just as you may be more drawn to, say, a Sonoma Valley Chardonnay, you too might find yourself drawn to ones grown with the Dijon clones.