Millesima Tips is a series of educational tutorials designed to help wine-lovers learn more about various subjects in the world of wine. Our handy guide provides useful information on the winemaking process, from pruning the vine to blending the wine, and everything in between. The second episode of our series explores grape varietals and how they affect the aromatic and flavour profile of the wines made from them. We will also see the reasons for why certain varietals are chosen for a given terroir and what determines the varietal blends of some of the world’s best wines.
The Biology of a Wine Grape Variety
The biological definition of a grape is the fruit (of the “berry” variety) produced by the woody vine of the plant genus Vitis. The genus includes around 60 known species. Grapes have historically been used to produce a variety of products – jam, juice, vinegar, dried raisins, grape seed extract and grape seed oil – as well as being eaten fresh, as table grapes. Most of the world’s wine is made from the common grape vine of species Vitis vinifera. However the North American Vitis labrusca (represented by Concord and Catawba grapes) and the phylloxera-disease-resistant Vitis riparia are also sometimes used in wine production. Grape varietals (or grape varieties) are different hybrids of the grapevine within each species. For the sake of clarity, this article will examine only the varietals of Vitis vinifera, as these are the best known and most widely associated with wine. As is the case with any biological species, each hybrid of Vitis vinefera can be identified by its own signature set of characteristics. When it comes to the fruit, this can mean a great diversity in grape size, skin colour, skin thickness and the chemical composition of the skin, pulp and seeds. So while varietals like Pinot Noir and Gamay are known to be thin-skinned and thus quite finicky and difficult to plant, others, including Grenache, Malbec and Cabernet Sauvignon are thicker-skinned and more resistant to harsh climates. The amount of tannin in the grape skin has a significant effect on the colour, aromatic bouquet and flavour profile of the resulting wine.
Effects of Terroir and Oak
While it is relatively common to assign certain characteristics to well-known grape varieties, the flavour profile of the resulting wine is also largely dependent on the geographical region in which the vines are grown and the special set of environmental conditions associated with that region. Perhaps the most significant environmental factor is climate, which can be cold, warm, continental, oceanic, etc. Sauvignon Blanc is an example of a grape varietal whose resulting wine differs significantly based on where the grapes are grown. Sauvignon Blanc wines from the cooler climate of the Loire Valley in France tend to be tight and crisp, while those of Marlborough in New Zealand burst with flavours of guava, honeydew melon and freshly cut grass. The composition of the soil in which the vines of a varietal are planted can also significantly affect the flavour of the wine. For example, Malbec grown in the limestone soils of France’s Cahors region tend to be highly tannic with notes of black fruit and later tobacco and meat, while Argentine Malbec grown in the alluvial sand and clay soils of Mendoza result in fruitier wines with sweet floral notes.
Beyond just the forces of nature, human intervention can also affect the expression of many varietals. A classic example is the effect of oak-ageing on the flavour profile and mouthfeel of a Chardonnay wine. Chardonnay aged in oak tends to reveal flavours of baked apples and hazelnuts as well as a very distinct creamy, buttery richness on the palate. This style of Chardonnay was very popular at one point in California. The unoaked Chardonnay popularised by the Chablis region of France, on the other hand, tends to be much lighter and crisper in the mouth with flavours of yellow apple, fresh pineapple, citrus peel and white flowers.
Blend or Single-Varietal
Wines can either be single-varietal (when made of grapes of just one grape varietals) or blends (when made by blending two or more varietals). Blends have the advantage of combining complementary flavour profiles of different varietals to produce a more balanced, well-rounded wine. Many wine regions particularly in the Europe have historically always produced blends of different naturally occurring local varietals. For example, the famous Bordeaux Blend uses Cabernet Sauvignon or Merlot as the base varietal, blending in Cabernet Franc, Petit Verdot and, occasionally, Carmenere. Wines of the Cotes du Rhone contain a blend of Grenache, Syrah and Mourvedre in which each of the three varietals lend a certain attribute to the wine. Another very famous blend, that of Champagne, combines Pinot Noir, Chardonnay and Pinot Meunier for body. Reflecting the stunning diversity of grape varietals in Portugal, certain Porto wines can contain up to 52 unique grape varietals blended together.
French Grape Varietals
Many of the most popular grape varietals used all over the world either originated in France or found their most famous expressions through French wines. And with close to 3,000 different wines produced from over 200 indigenous wine varieties in the many thousands of wineries, it is not difficult to believe it. And while it would take far too long to list all of France’s wine varietals, the classic blends and regional variations, we can consider some of the most famous. Pinot Noir is a finicky red wine varietal that can be used to produce sparkling, white, rose and red wines. In France, it is most significantly produced in Burgundy and Champagne, but it has also been planted in similar climates all over the world. Grenache, popular in the Rhone Valley and Southern France is a tough and sturdy grape used to produce full-bodied, fruit-forward red wines. The smooth red wines of Merlot play a key role in the Bordeaux Blends of the Right Bank. On the Left Bank of Bordeaux, Cabernet Sauvignon reigns supreme. As the most planted red wine grape in the world, Cabernet Sauvignon has found a wide variety of expressions. Meaty, peppery Syrah is most popular in the Rhone Valley and Southern France but has also become very popular in Australia, the USA and South Africa. The black fruit flavoured Malbec, originally from France, has found a new home in Argentina where close to 70% of the varietal is now produced. Other famous red French varietals include Cabernet Franc, Carignan, Cinsault, Gamay and Mourvedre.
No doubt the most popular white varietals from France are Chardonnay and Sauvignon Blanc, which are now produced in diverse wine regions throughout the world. Chenin Blanc, originally from and popular in the Loire Valley is also the most widely planted variety in South Africa. Viognier, made famous by the wines of the Rhone Valley, is now also popular in the USA and Australia. And Semillon, the base of White Bordeaux blends – among which most famous is the sweet wine Sauternes – is also widely grown in the Hunter Valley of Australia and in South Africa.
Non-French Grape Varietals
While many of the world’s most widely planted varietals are of French origin, Italy is also home to a dizzying array of indigenous varieties, many of which have gained international fame. Italian red varietals include the lightly coloured and highly tannic Nebbiolo of the Piemonte region and the robust, cherry-fruit-forward Sangiovese of Tuscany. Tempranillo is a black grape varietal of Spanish origin, which has also become very popular in New World wine regions.
While the aromatic Gewurtwraminer famously produced in the Alsace region of France and in Germany, it is believed to be from Italian origin. Native to the Rhine area of Germany is Riesling, a white varietal known for producing beautifully full-bodied, dry and sweet wines with a distinct floral fragrance. One of the oldest planted grape varietals is Muscat, dated back to the ancient Greek and Roman empires. Although the origin of this varietal is not known for certain, nowadays it finds its clearest expressions in the sparkling Moscato d’Asti, still Moscato and dessert Moscato wines of Italy.