Cabernet Sauvignon - Winemaking

Winemaking

In many aspects, Cabernet Sauvignon can reflect the desires and personality of the winemaker while still presenting familiar flavors that express the typical character of the variety. The most pronounced effects are from the use of oak during production. Typically the first winemaking decision is whether or not to produce a varietal or blended wine. The "Bordeaux blend" of Cabernet Sauvignon, Merlot and Cabernet franc, with potentially some Malbec, Petit Verdot or Carménère, is the classic example of blended Cabernet Sauvignon, emulated in the United States with wines produced under the "Meritage" designation. But Cabernet Sauvignon can be blended with a variety of grapes such as Shiraz, Tempranillo and Sangiovese. The decision to blend is then followed by the decision of when to do the blending—before, during or after fermentation. Due to the different fermentation styles of the grapes, many producers will ferment and age each grape variety separately and blend the wine shortly before bottling.

The Cabernet Sauvignon grape itself is very small, with a thick skin, creating a high 1:12 ratio of seed (pip) to fruit (pulp). From these elements the high proportions of phenols and tannins can have a stark influence on the structure and flavor of the wine—especially if the must is subjected to long periods of maceration (skin contact) before fermentation. In Bordeaux, the maceration period was traditionally three weeks, which gave the winemaking staff enough time to close down the estate after harvest to take a hunting holiday. The results of these long maceration periods are very tannic and flavorful wines that require years of aging. Wine producers that wish to make a wine more approachable within a couple of years will drastically reduce the maceration time to as a little as a few days. Following maceration, the Cabernet must can be fermented at high temperatures up to 30 °C (86 °F). The temperature of fermentation will play a role in the result, with deeper colors and more flavor components being extracted at higher temperatures while more fruit flavors are maintained at lower temperature. In Australia there has been experimentation with carbonic maceration to make softer, fruity Cabernet Sauvignon wines.

The tannic nature of Cabernet Sauvignon is an important winemaking consideration. As the must is exposed to prolonged periods of maceration, more tannins are extracted from the skin and will be present in the resulting wine. If winemakers choose not to shorten the period of maceration, in favor of maximizing color and flavor concentrations, there are some methods that they can use to soften tannin levels. A common method is oak aging, which exposes the wine to gradual levels of oxidation that can mellow the harsh grape tannins as well as introduce softer "wood tannins". The choice of fining agents can also reduce tannins with gelatin and egg whites being positively-charged proteins that are naturally attracted to the negatively-charged tannin molecules. These fining agents will bond with some of the tannins and be removed from the wine during filtration. One additional method is micro-oxygenation which mimics some of the gradual aeration that occurs with barrel aging, with the limited exposure to oxygen aiding in the polymerization of the tannins into larger molecules, which are perceived on the palate as being softer.