A varietal wine is a wine made primarily from a single grape variety.
The most important wine grapes harvested around the world.
There are so many different types of wine grapes, it’s easy to understand why people quickly get confused. We have selected the ten most important varieties and here we provide a brief description of the grapes, the wine they produce and where they are grown.
Cabernet Sauvignon
\Cab-air-nay So-veen-yawN\ (French) The parent of all red Bordeaux varietals , this vine is an infant as far as French grape varieties go. Cabernet Sauvignon has only been widely planted in France’s Bordeaux region since the 18th century. Brought to California in 1857, along with the Pinot Noir grape. By the turn of the century, Cabernet was recognized as the premier red grape of the state. Cabernet Sauvignon is known for its depth of flavor, aroma and ability to age. Cabernet Sauvignon is a vigorous vine that grows quite easily in a variety of different soils, to ripen properly it requires well drained soils. Cabernet Sauvignon grapes grow best in places where it can bask in the sun, like California’s Napa Valley.
Cabernet Sauvignon grapes which have been grown in warm climates tend to produce wines with flavors of black currant, cherries and ripe red fruits. Wines made from Cabernet Sauvignon grapes which have been grown in cooler climates tend to have more herbaceous notes, like that of eucalyptus and green peppers.
California is the second largest producer of Cabernet Sauvignon grapes in the world. The Bordeaux region in France is the largest. 
Cabernet Franc
\Cab-air-nay FrahN\ (French) This French variety is many times blended with Cabernet Sauvignon. Cabernet Franc tends to be lighter in color and body, with more immediate fruit than Cabernet Sauvignon.Adapts well to cooler areas, especially the northeast and Great Lakes regions. In particular, Long Island, with its maritime climate, has produced excellent Cabernet Franc. It does well as both a varietal wine and as a component of Bordeaux-type blends. Cab Franc while young has aromatic and fruity flavors of raspberries, cherries, plums, strawberries, violets, currants and herbs. When blended with the more astringent Cabernet Sauvignon, allows some of Cabernet Sauvignon’s more reclusive charms to come out.
When Cabernet Franc is bottled as a varietal, it makes a leaner, fresher style of Cabernet, designed for earlier consumption. In cooler regions, Cabernet Franc’s earlier ripening is a significant advantage over Cabernet Sauvignon. It is this factor that makes Cabernet Franc the preferred Cabernet in the shorter season of cool-climate vineyards like those of the northeast and the Great Lakes 
Merlot
\Mare-low\ (French) The most planted red grape in the Bordeaux region of France, Merlot is popularly associated with the great wines of Saint-Emilion and Pomerol and is on a metoric rize in populaity in the new world. The Merlot grape can be traced back all the way back to the first century in France. It is an early ripening grape that is harvested well before winter sets in.Therefore, they’ve always been able to thrive in colder climates and in soils that are too poor and too cold for Cabernet Sauvignon. Merlot is medium to full body with black cherry and herbal flavors, typically smooth, soft and mellow.
Much of the Cabernet Sauvignon sold in the U.S. actually has small amounts of Merlot blended in to help tame the Cabernet’s mighty tannins.
The world’s most famous producer of French Merlot is Chateau Petrus and the 1998 Chateau Petrus Merlot. 
Pino Noir
\Pee-noe-Nwahr\ (French) A good bottle of Pinot Noir has some of the headiest aromas and the liveliest flavors of any wine. The delicate vine, one of the oldest French varietals, was named by the noble Pinot family after the pinecone shape of the grape bunches. Pinot has been cultivated continuously in Burgundy, France, since the 1st century AD. One legend has it arriving via the Romans. Others say the Romans arrived to find Pinot already established in the region. The wine this vine is capable of producing is nothing short of astonishing. The wine’s unique flavors and textures make it very “food friendly.” Rich foods like salmon, duck,
and ribs taste especially good. Its smoky quality pairs nicely with grilled meats and wild game such as pheasant.
Pinot Noir evolves as it matures. The young wine will have fruit flavors of cherry, plum, raspberry and strawberry. In time, more complex flavors emerge, often expressing hints of chocolate, earthiness, smoke and truffles. 
Riesling
/ˈrēzliNG/ Riesling is an aromatic grape variety displaying flowery, almost perfumed, aromas as well as high acidity. It is used to make dry, semi-sweet, sweet, and sparkling white wines. Riesling wines are usually varietally pure and are seldom oaked. In terms of importance for quality wines, it is usually included in the “top three” white wine varieties together with Chardonnay and Sauvignon blanc. Riesling is a variety which is highly “terroir-expressive”, meaning that the character of Riesling wines is greatly influenced by the wine’s place of origin. In cool climates (such as many German wine regions), Riesling wines tend to exhibit apple and tree fruit notes with noticeable levels of acidity that are sometimes balanced with residual sugar. In Australia, Riesling is often noted for a characteristic lime note that tends to emerge in examples from the Clare and Eden Valley in South Australia.
Riesling is a versatile wine for pairing with food, because of its balance of sugar and acidity. It can be paired with white fish or pork, and is one of the few wines that can stand up to the stronger flavours and spices of Thai and Chinese cuisine.. 
Sangiovese
\Sahn-joe-VAY-zeh\ (Italian) Sangiovese is the great Italian grape that forms the basis for Chianti. It is also a major grape in many of the prestigious wines known as Super Tuscans. The vine itself, believed to have probably been indigenous to Tuscany, is of truly ancient origin. Site selection is important too as not all clones thrive in the same soils and exposures. This means that wines made from the grape can vary widely in style and quality. Some sangioveses are thin and watery while others can be earthy, rich, and complex. When young it can be reminiscent of warm cherry pie. As it ages it takes on flavors of prunes, dark cherry, dried orange peel, tea, dried leaf, and other earthy flavors.
The grape came to America with the Italian immigrants in the late 1880s and early 1890s. You’ll now find the grape hailing from New York and Long Island, Pennsylvania, Ohio, Texas, New Mexico, Arizona, Colorado, and as far north as Washington state. 
Syrah / Shiraz
/ Sirah \See-rah\ (French) A voluptuous grape, known as Syrah to the French and Shiraz to Australians, hails from France’s Rhone River Valley. It has a beautiful, thick, soft texture, rich flavor, full body, and the unique ability to deliver savory and sweet spice on the palate. In its homeland, between Lyon and the Mediterranean, the vines alternately bask in sun light and rain.The grape is quickly gaining popularity with Oregon, New York, and Washington state vintners. The reason is simple: Syrah is considered one of the “noble” grapes, capable of producing serious, long-lived red wines that can age beautifully for decades.
The Syrah-based wines of France, such as Châteauneuf du Pape, are legendary. Syrah is typically described as having aromas and flavors of blackberry, cassis, black pepper, and smoke. 
Zinfandel
\Zin-fahn-DELL\ (Italian)
The Zinfandel grape found its way to California in the late 1860’s. and became an American classic from the start. Before Prohibition, Zinfandel was California’s most popular and successful variety.
Zinfandel seems to produce grapes of the best quality in cooler Coastal regions. Cool nights foggy mornings, and hot sunny afternoons allow the grapes to mature slowly and retain their natural fruit acidity even as they gain in sugar content.
Zinfandel favors hillside planting, as good drainage is essential. If the vines absorb too much water from the ground after a rain, the grapes will swell and some will burst, or the cluster may ferment from inside out while still on the vine.
Younger vines are often used to make that summer refresher, White Zinfandel.
Source: wineturtle.com