Making Red Wine

In general, well-made red wines have more flavour components and are typically more complex than white wines. Although red wine may be nearly as acidic as white, red wine usually has a wider range of fruit flavours, as well as a noticeable amount of tannin: qualities best appreciated at warmer temperatures.

The Importance of Tannin

Red wine can only be made from black (or red) grapes. Whereas most grapes contain the same greenish pulp, the skins of red-wine grapes give red wine its colour, tannin and assorted fruit flavours. Tannin is the essential difference between red and white wines. It is a powerful preservative, and since red wines are often made to mature over many years, tannin is required to ensure the wine does not grow old prematurely. So white grape skins, which add little to white wine, are removed early in the winemaking process, but red grape skins are kept in the fermenting vat for an extended period of time.

Red wines destined for early or short term drinking (and not for laying down) are made with little or no tannin in their composition. Traditionally these were generally peasant wines, made to be drunk with the daily meal and without ceremony. However, nowadays many fine, modern wines are made for immediate consumption. Since these wines don't need to last several years, the bitter tannins are excluded and the wine tastes fruity, fresh and approachable upon release.

The Process

The red wine making process is essentially the same as the white wine process:

• gathering the grapes
• fermentation
• maturation
• bottling

At various stages the winemaker can intervene to change the style of the wine they are making.

Crushing the Grapes

It is usually necessary to remove the stalks from red wine grapes as they are crushed, so that they do not give excessive tannin to the wine. Thus a combination crusher/de-stemmer is used to prepare red grapes for fermentation rather than the simple crusher used for white grapes.

Fermentation

The resulting mash is run straight into the fermentation tank without pressing. The fermentation vats may be concrete, steel or, more traditionally, oak. The grape skins tend to rise to the top of the fermenting must, forming a 'cap' on top of the juice. In order to extract the desirable qualities from the skins, this cap must be continuously mixed back into the juice. This can be done by one of three methods. The first involves pumping juice from the bottom of the barrel over the cap - called 'pumping over'. The second, 'punched cap fermentation', manually punches the cap back into the juice with a special paddle. The third option is to fit a mesh filter below the surface of the wine.

As in white wine production, temperature control is important, although red wines benefit from a fermentation temperature a little higher than that which is ideal for whites. Temperatures vary between around 18 and 28°C. After fermentation is complete (anywhere between a few days and six weeks), the new wine is drawn from the vat.

Free Run Wine

The first run of juice, called 'free-run' wine, is so-called as it drawn from the tank without any pressure. Forcibly squeezing the juice from the must would extract too much tannin. This 'free run' wine is poured straight into barrels or stainless steel to rest and mature. Only after the free-run juice is removed is the remaining mulch of juice, skins, and stalks squeezed, yielding a strong, tannic liquid known as 'press wine'. A portion of this might be blended with the free-run juice in order to adjust the tannin level carefully.

Settling and Maturing

The wine is then clarified in much the same manner as white wine and transferred to ageing barrels, where it can slowly mature. Racking may be necessary every few months if the wine is held in the cellar for a length of time. Prolonged barrel ageing before bottling is desirable for most types of red wine, since the broad array of flavour components generally needs more time to harmonize in red wines than in white wines. Most of the great red wines are matured in oak barrels. Oak from ancient French forests is generally agreed to be the finest, imparting a subtle vanilla, toasty flavour. American oak is regarded as imparting a 'bigger', less subtle, spicy flavour to wine. Oak from the Ukraine, Poland and Slovenia is also used, but many experts find it is not flavourful enough.

Bottling and Resting

When wine is deemed ready for release, it is transferred to bottles in a mechanised process. Air is regarded as the enemy, and care is taken not to allow its contact with the wine during bottling. For the finest wines, it is often advantageous for the winery to then keep the bottles in storage for two or more years. This makes for better wine when it finally reaches the shop, and in many cases the value of the wine will also have increased greatly during its rest.