The starting point for making red wines, as with white wines, comes with crushing and destemming the red or black-skinned grapes. Occasionally the winemaker may decide not to destem, as the stems will add further flavour compounds and tannins to the grape must. The crushed grapes are then moved into the fermentation vessel. Stainless steel tanks are the most common vessel for the fermentation of red wines, as they allow easy access to the liquid for mixing the grape skins with the liquid, and also provide for temperature control.
The addition of yeast starts the fermentation, and sulphur dioxide helps to prevent oxidation. The carbon dioxide produced by the fermentation process means that all of the solid material soon rises to the surface of the fermentation vessel. These solids need to be mixed thoroughly with the liquid in order to extract the colour, phenolics, flavour compounds and tannins which are vitally important to red wines. To do this, the winemaker can either punch down the cap of solids using rods (similar to oversized potato mashers), or the liquid can be pumped over the top using a hose pipe. This process is known as maceration.
The liquid will then be separated from the skins prior to the secondary malolactic fermentation. Unlike white wines, almost all red wines undergo malolactic fermentation, as the wines would otherwise be too harsh to enjoy.
After the malolactic fermentation, the red wine is ready for barrel maturation or bottling. If the wine is destined to be bottled without barrel ageing, it will undergo fining, blending, stabilisation and bottling. If the wine is destined for barrel ageing, it will be moved into barrels for the appropriate amount of time, with regular topping up to replace the evaporated liquid and prevent oxidation before going through the bottling process. It may also then be bottle aged before it is ready to drink.
Cabernet Sauvignon is one of the most widely planted red grape varieties in the world and is suited to a wide range of climates. Together with Cabernet Franc and Merlot, it makes some of the world's best wines in Bordeaux, but it is also very successful as a single varietal in Tuscany, Australia (especially Coonawarra and Margaret River), California, Chile, Argentina and South Africa. It produces medium-full bodied wines with black fruit (especially blackcurrant), herbaceous or menthol notes and has medium-high acidity and high tannins. Oak ageing adds extra spice and complexity to the wines, which can age very well in bottle for decades.
Merlot is a highly successful variety and is grown across the world. In moderate climates it gives wines with red fruit flavours, medium body, medium acidity, medium alcohol and medium-low tannins, making it the perfect grape for soft, fruity and early drinking wines. In warmer climate is gives a much richer and fuller wine with black fruits, high alcohol and ripe tannins. Oak ageing adds complexity to these dark wines, and they can age very well in bottle. Along with Cabernet Sauvignon and Cabernet Franc, Merlot is one of the most important varieties in the fine wines of Bordeaux, especially Pomerol and St Emilion, but it is also highly successful in Italy, Australia, New Zealand, California, Chile, Argentina and South Africa.
Pinot Noir is the classic red variety of Burgundy, where it produces delicate wines of great intensity and longevity. Pinot Noir is notoriously difficult to grow, and is best suited to cool, moderate climates. It produces light-medium bodied wines with red fruit and can have vegetal / earthy notes. It has medium-high acidity and very soft, silky tannins which can add a richness to the texture. It is very successful in Burgundy, where it produces some of the worlds finest wines, Loire, cool-climate parts of Australia (Mornington Peninsula is highly successful), New Zealand, California, Oregon, Chile and South Africa.
Tempranillo the classic variety of Rioja, Tempranillo produces medium-bodied wines with over-ripe strawberry and plum flavours, medium-high acidity and medium-high tannin. With oak ageing it gains earthy, savoury notes such as leather and oak spice, and can also have flavours of coconut and vanilla from American oak. It can have excellent ageing potential. As well as being the mainstay of Rioja, Tempranillo also produces the great wines of Ribera del Duero and Toro, and is widely planted across Spain. It is also widely planted in Northern Portugal and is an important variety in Port. Tempranillo is known by a variety of synonyms, including Cencibel, Tinto Fino, Tinto del Toro and Tinto Roriz.
Syrah (Shiraz) A hugely successful variety across the world, Syrah / Shiraz gives spicy wines with black fruit, dried fruit, jam and chocolate flavours. It is usually full bodied with high tannins and high acidity. Oak ageing adds toasty, smokey complexity to the wines, the best examples of which can age for decades. Perhaps best known as Shiraz from Australia, where it makes many excellent wines, Syrah is also responsible for the great wines of the Northern Rhône, Hermitage, Cornas, St-Joseph and Cote Rotie. It is also an important variety in the Southern Rhône, and is highly successful in South Africa, New Zealand, Chile and California.