The Grape Story Part 1 - What is a Grape Variety?
The grape varieties we see on a daily basis are only a small fraction of a much larger and complex family. Biologically, they belong to the Vitaceae Family, of the Genus Vitis, Sub-genus Euvites (the other genus being Muscadinia), Species Vinifera (there are several other species within the same sub-genus).
To give some context, there are 79 different accepted species within the Euvites sub-genus and, within the Vitis Vinifera species, exist over 1000 different grape varieties. While this gives the grower plenty of choice when deciding which variety to plant, it can be extremely complicated for many wine drinkers to understand.
To make things even more exciting, as with other plants and animals, the grape vine throws up natural mutations over time. These mutations could be subtle, such as tighter bunched grapes, fatter grapes, or smaller, more concentrated grapes, or enormous, as is the case when a red variety suddenly produces a bunch containing white grapes (grapes with no skin pigments). If cuttings were taken from this arm and planted out, a new variety which shares a similar DNA profile with the parent (red) grape, but shows different physiological traits, could begin life.
This is indeed how varieties such as Pinot Blanc, Pinot Meunier and Pinot Gris (known as Pinot Grigio in Italy) began life, from a Pinot Noir mutation.
Within Pinot Noir itself there are several dozen clones available. A clone is made by taking cuttings from a single original plant; therefore, the clone is genetically identical to its parent plant. For example, the Pinot Noir AM 10/5 clone, which was largely planted out in New Zealand in the 1970’s, was taken from the 5th vine in the 10th row of Anton Meier’s original vineyard in Switzerland. Today, clonal research is carried out by dedicated Universities and research centres, whose name is often given to the clone - Dijon clone 777, 116, 117, and UC Davis Clone 6 and 7, are a few examples.
Research into grape varieties has been going on for as long as man has grown grapes commercially. Riesling has been a German darling for centuries, but it is a notoriously late ripening variety in Germany. However, varieties such as Silvaner ripen relatively early. Could it be that by crossing Silvaner and Riesling, one could produce a variety with Riesling-like characteristics, which ripened earlier like Silvaner?
This question gave rise to a whole load of German crosses (a crossing is variety spawn by breeding varieties within the same species). Varieties such as Bacchus (Riesling X Silvaner X Muller-Thurgau) and Muller-Thurgau (Riesling X Madeliene Royale) are both very successful crossings. However, crossings aren’t always successful; just because your mother is athletic and your father is academic, doesn’t mean you’ll grow up to be an athletic-academic.
Crossing also certainly happened naturally and DNA profiling has helped to fill in some of the gaps in our knowledge of the ancestry of some ancient varieties. Cabernet Sauvignon for example, has been shown to be an offspring of Sauvignon Blanc and Cabernet Franc, while Chardonnay has been shown to be a descendant of Gouais Blanc.
Once research into crossings was on its way, it was only a short step to producing hybrids. If a crossing is the product of two varieties belonging to the same species, a hybrid is the product of varieties belonging to two different species. While hybrids generally have an unfairly poor reputation, a successful hybrid such as Vidal Blanc (Ugni Blanc X Seibel 4986) is responsible for some of Canada’s most delicious Ice Wines.
All quality wine produced in the E.U must be made from 100% Vitis Vinifera varieties, or from varieties with a special exception. These varieties need to be tested to determine if they have enough Vitis Vinifera in their parentage and have to pass a tasting test; hence hybrid varieties such as Rondo and Regent, which are permitted for making quality wine in England.
Other Grape Species
On the face of it, other Vitis species such as Berlandieri, Riparia, and Rupestris might seem purposeless, but this couldn’t be further from the truth and modern grape growing wouldn’t be what it is today without these unsung heroes.
It is common knowledge that soils differ from region to region and, sometimes, even within the same region. The limestone rich soils of Champagne can prove problematic for grape growing and Champagne vines often suffer from Chlorosis (a yellowing of the leaves due to lack of nutrients - in this case iron, which is locked in the soils due to the high calcium carbonate content). However, Vitis Berlandieri roots can tolerate soils with high lime content and are invaluable for growers in such regions. The Champagne governing body – CIVC – states that 81% of Champagne vines are planted on 41B rootstocks, which are a Berlandieri descendant.
The question then is, with such a wide range available, why then is there such a limit to the grape varieties to which we are exposed? I challenge you to name even 20 white grape varieties!
Climate, appellation rules and the global wine market all play a part in determining which grape varieties get a slice of the pie.
For example, a grower in Marlborough, New Zealand, is more than likely going to be planting some Sauvignon Blanc, because not only are the weather and climate suitable to this variety, but the current market also has an unquenchable thirst for New Zealand Sauvignon. A grower in Bordeaux couldn’t suddenly start planting Pinot Noir (or other, more unusual varieties) as the appellation rules do not permit the use of non-traditional Bordeaux grapes, even for the most basic Bordeaux category – Bordeaux A.C.
In the wake of Phylloxera, the vine disease which swept through Europe in the 19th century, the Italians estimate that several hundred different indigenous grape varieties were lost as growers switched to higher yielding cultivars.
In conclusion, the grape family is a complex and fascinating one, with enough twists, turns, revelations and intrigues to make even George R.R. Martin hang his head in disbelief.
Here are a few unusual grape varieties for the adventurous:
- Grüner Veltliner
Read part 2 of the series: what is terroir?