Red wine is made from red grapes; as most red grapes have juice that is clear, the color of a red wine is the result of skin contact during maceration prior to fermentation.

Red Wine Varietal Groups

These are the main groupings of red grape varietals (or more strictly speaking grape varieties) used in the vast majority of red wine production around the world.

Red Bordeaux Varietals
Bordeaux varietals is a term used to describe wines exclusively produced of the Cabernet Sauvignon, Cabernet Franc, Malbec, Merlot and Petit Verdot grapes. These wines can either be produced from 100% of a single varietal or a blend of 2 or even all 5 varietals. Carménère is sometimes also considered amongst the Bordeaux varietals, but most often this group is limited to just the 5 previously mentioned varietals. These varietals were original cultivars of the Bordeaux region of France where they thrived and were later transplanted around the world as far as the US, Argentina, Chile, Australia and New Zealand.

Red Burgundy Varietals
Burgundy varietals is a term used to describe wines produced of the Pinot Noir and Gamay grapes. These wines can either be produced from 100% of a single varietal or a blend. These varietals were original cultivars of the Burgundy region of France where they thrived and were later transplanted around the world.

Red Rhone Varietals
Rhone varietals is a term used to describe wines produced of the Syrah, Grenache, Carignan, Cinsault, and Petite Sirah grapes. These wines can either be produced from 100% of a single varietal or a blend. These varietals were original cultivars of the Rhone region of France where they thrived and were later transplanted around the world. Syrah and Mourvedre tend to be full-bodied, rich, and flavorful reds while Grenache and Carignane tend to the lighter side of the spectrum.

Red Zinfandel
Zinfandel came to American shores by way of the Schonbrunn collection which contained all the wine varietals grown in the Austrian empire. The earliest mention of Zinfandel, by name, in America was a vine nursery in Long Island in the 1820s. It made its way to California in the gold rush and thrived because of its hearty constitution and vigorous yields. Many a prospector had a little vineyard of Zinfandel and washed away their sorrows in their purple cups. As the 19th turned to the 20th century, it thrived as a potent source of table wine (Gallo’s jugs of Hearty Burgundy were made from old vine Zin). Ironically, it was the development of White Zinfandel that saved many of the great old vineyards, which are now yielding world-class wines. The Blush explosion of the seventies meant there was a reason not to rip up Zin for other newly popular grapes. 
Red Hybrids
Hybrid wines refer to US wine varietals that are a crossbreeding of European vinifera wine grapes and indigenous American wine grapes that have hearty rootstocks well adapted to the US climate. Chambourcin and Norton are the two most important red hybrid varietals in the US; they are capable of making world-class wines.

Other Reds
This category is reserved for regional varietals and blends that do not fit into other established categories. Examples of varietals included as part of this category are Bonarda, Baco Noir, Primitivo, Frontenac, Blaufrankish (aka Lemburger) and an endless combination of blends.